1.1. Contact organisation
Central Statistics Office (CSO), Ireland
1.2. Contact organisation unit
National Accounts and Prices Directorate / Prices Division.
1.3. Contact name
Restricted from publication
1.4. Contact person function
Restricted from publication
1.5. Contact mail address
Consumer Prices, Central Statistics Office (CSO), Skehard Road, Mahon, Cork, IRELAND
1.6. Contact email address
Restricted from publication
1.7. Contact phone number
Restricted from publication
1.8. Contact fax number
Restricted from publication
2.1. Metadata last certified
2 February 2026
2.2. Metadata last posted
2 February 2026
2.3. Metadata last update
2 February 2026
3.1. Data description
The harmonised index of consumer prices (HICP) is a consumer price index (CPI) that is calculated according to a harmonised approach. It measures the change over time of the prices of consumer goods and services acquired by households (inflation).
Due to the common methodology, the HICPs of the countries and European aggregates can be directly compared.
3.2. Classification system
The HICP uses the European classification of individual consumption according to purpose (ECOICOP), version 2.
3.3. Coverage - sector
The HICP covers the final monetary consumption expenditure of the household sector.
3.4. Statistical concepts and definitions
The main statistical variables are price indices. There are no discrepencies from the European Statistical System standards.
3.5. Statistical unit
The basic unit of statistical observation are prices for consumer products.
3.6. Statistical population
Please see the information under the next points.
3.6.1. Statistical target population
The target statistical universe is the 'household final monetary consumption expenditure' (HFMCE) on the economic territory of the country by both resident and non-resident households. The household sector to which the definition refers, includes all individuals or groups of individuals irrespective of, in particular, the type of area in which they live, their position in the income distribution and their nationality or residence status. These definitions follow the national accounts concepts in the European System of Accounts.
3.6.1.1. Statistical target population - national specifics
None.
3.7. Reference area
Please see the information under the next point.
3.7.1. Geographical coverage
The HICP refers to the economic territory of a country as referred to in paragraph 2.05 of Annex A to ESA 2010, with the exception that the extraterritorial enclaves situated within the boundaries of a Member State or a country are included and the territorial enclaves situated in the rest of the world are excluded.
3.8. Coverage - Time
Please see the information under the next points.
3.8.1. Start of time series
The HICP series started in January 1997.
3.8.2. Start of time series - national specifics
See the HICP database.
3.9. Base period
2025=100.
The following units are used:
- Index point
- Percentage change on the same period of the previous year (rates);
- Percentage change on the previous period (rates);
- Percentage share of the total (weights).
HICP is a monthly statistics.
6.1. Institutional Mandate - legal acts and other agreements
Harmonised Indices of Consumer Prices (HICPs) are harmonised inflation figures required under the Treaty on the Functioning of the European Union. Regulation (EU) 2016/792of the European Parliament and the Council of 11 May 2016 (OJ L 135) sets the legal basis for establishing a harmonised methodology for the compilation of the HICP and the HICP-CT.
This regulation is implemented by Commission Regulation (EU) 2020/1148&of 31 July 2020.
Further legislation is available in the web page Legislation - Harmonised Indices of Consumer Prices (HICP) - Eurostat.
Other methodological documentation, namely recommendations and guidelines, is available in the HICP dedicated section, under 'Methodology'.
6.1.1. Legal acts - deviations
The Irish HICP follows the relevant HICP legislation. More information on Compliance can be found under the point on quality management.
6.1.2. National legal acts and other agreements
Specific national legislation has not been implemented for HICP price collection, standards, datasets or methodology nor is there legislation that restricts the implementation of HICP standards etc.
However, more generally Article 29 of the Statistics Act 1993 empowers officers of statistics (e.g. price collectors) to enter premises as required. Article 29 reads as follows:
29.-An officer of statistics may at all reasonable times, on production of his certificate of appointment if demanded, enter any premises for the purposes of-
-
- delivering a notice under section 26 of this Act, or
- delivering or collecting forms, questionnaires, records or information, or
- making any such inquiries as he is authorised to make under this Act.
Article 29 covers the price collection in retail outlets. However, it does not cover the entirety of price collection for HICP e.g. phone and postal surveys managed centrally. We are, therefore, considering introducing specific legislation in order to translate the new EU HICP Framework Regulation into national law.
Statutory Instrument 313/2017 - Statistics (Consumer Price Survey) Order 2017, refers to requirement for information to be supplied upon request.
6.1.3. Access to administrative data
National authorities are obliged by law to grant access to administrative data for the purposes of price statistics. PART IV (Use of Records of Public Authorities for Statistical Purposes) of the Statistics Act 1993 provides the right of access, subject to some limitations and conditions, of the CSO to administrative records held by public authorities for statistical purposes.
Access to transaction data is covered by the statutory instrument covering the Consumer Price Index: 'Statistics (Consumer Price Survey) - order 2022'.
6.1.4. Organisation unit - portfolio
Within the CSO there are three main Statistical Directorates; Social & Demographic, Economic and Business.
Within each of these, there are a number of divisions. CPI falls under the Prices division which is under the Business Directorate.
Statistics released under the prices division include:
- Wholesale Price Index
- CPI/HICP
- Agricultural Price Indices
- Services Producer Price Index
- Comparative Price Levels for Food, Beverages and Tobacco
- Residential Property Price Index
- Agricultural Land Prices
6.1.5. Regional organisation of consumer price statistics
No regional offices in Ireland.
6.2. Institutional Mandate - data sharing
None.
7.1. Confidentiality - policy
Regulation (EC) No 223/2009 of the European Parliament and of the Council, of 11 March 2009, on the transmission of data subject to statistical confidentiality to the Statistical Office of the European Communities.
7.2. Confidentiality - data treatment
HICP data at ECOICOP 2-digit level is published nationally and is transmitted to Eurostat at ECOICOP 5-digit level. Individual or identifiable price data is not published.
8.1. Release calendar
The HICP is released according to Eurostat’s Release calendar.
The calendar is publically available and published at the end of the year for the full following year.
8.2. Release calendar access
Eurostat's website: HICP Release calendar.
8.3. Release policy - user access
In line with the Community legal framework and the European Statistics Code of Practice Eurostat disseminates European statistics on Eurostat's website (see point 10 - 'Accessibility and clarity') respecting professional independence and in an objective, professional and transparent manner in which all users are treated equitably. The detailed arrangements are governed by the Eurostat protocol on impartial access to Eurostat data for users.
At national level, the CSO disseminates CPI/HICP data on the CSO website at 11am (local time) on the day of publication (see point 8.2).
The headline CPI/HICP figures are provided to senior officials in the Office of the Prime Minister, the Ministry of Finance and the Central Bank under embargo one hour before the release of the CPI/HICP publication.
HICP data is transmitted to Eurostat under embargo, if the national CPI publication (which contains HICP data) is scheduled to be published after the deadline for transmission of data to Eurostat.
Monthly.
10.1. Dissemination format - News release
HICP publication is included as part of the national CPI release monthly.
10.2. Dissemination format - Publications
At national level: HICP data at ECOICOP 2-digit level are published in the Consumer Price Index monthly publication which is available on the CSO website.
10.3. Dissemination format - online database
HICP data is available through 'pxStat' on the CSO website.
10.3.1. Publication levels
HICP is disseminated to 2 decimal places. The language for dissemination is English.
There is only an electronic release and no paper dissemination. Paper copies of the release are only possible by printing the electronic release.
Monthly and Annual HICP data is available through CSO website via Statbank (CSO Main Data Dissemination Platform).
10.3.2. Publication by regions
No dissemination by regions.
10.3.3. Publication by households
No dissemination for different households.
10.4. Dissemination format - microdata access
None.
10.5. Dissemination format - other
None.
10.6. Documentation on methodology
The HICP Methodological Manual 2024 provides the reference methodology for the production of HICP , together with more recent methodological developments which can be found in legislation, methodological notes and guidelines.
10.6.1. Further methodological guidelines available at national level
At national level: HICP methodological notes are available with the monthly Consumer Price Index publication (background notes). A further detailed methodological description is available in the 'Consumer Price Index Introduction of Updated Series (Base: December 2023 = 100)' document which is available on the CSO website.
10.7. Quality management - documentation
The following list of reports have assessed the quality of the Irish HICP/CPI in recent years:
- Eurostat: Compliance Monitoring Report of 2010 and follow-up report of 2020.
- National: Consumer Price Index Review Group Report March 2010.
- National: Standard Report on Methods & Quality for CPI/HICP 2022.
11.1. Quality assurance
See information under the next points.
11.1.1. Quality management - Compliance Monitoring
The document HICP Compliance Monitoringdetails the compliance monitoring process.
11.1.2. Quality assurance - national specifics
Eurostat carried out a HICP compliance monitoring visit in May 2017 and published a report in September 2017. A follow up report was completed in early 2020.
Price collectors were suspended since March 2020 so no verification was taking place. Previous to this audits were carried out in the field sporadically to ensure price collection was correct.
A reduced number of price collectors have gone back into the field since the end of the Covid 19 Pandemic. This is as a result of an increased number of stores providing us with transaction data and a move to more online pricing taking place centrally in the CSO offices. A lot of large retailers in Ireland are nationwide and have a national pricing policy so there is very little regional difference in prices.
Price changes for prices collected in store are sent with indication codes and the items with sale or any other change that should be noted are checked by staff in the office. For transaction data, an automated system identifies outliers in the data so it can be queried or removed if necessary.
Each item relative is then reviewed to identify outliers.
11.2. Quality management - assessment
See information under the next points.
11.2.1. Compliance monitoring - last report and main results
The last available compliance monitoring or follow-up reports can be found in the dedicated HICP part of Eurostat’s website, under ‘Quality.
11.2.2. Quality assessment - national specifics
HICP concepts and methodology have been developed according to international standards and using consumer price statistics experience from all EU Member States. HICPs are considered to be sufficiently accurate for all practical purposes they are put into. In particular, it is the best measure of inflation for the euro area and the European Union as a whole as well as for the comparisons of inflation across countries for which it is compiled.
As with other member states, further work is ongoing to improve the quality of the index. Key priorities are the treatment of owner occupied housing (currently excluded) and greater harmonisation of methods for quality adjustment and sampling.
12.1. Relevance - User Needs
In addition to being a general measure of inflation, the HICP is also used in the areas of:
- wages, social benefit and contract indexation
- economic forecasting and analysis
- measuring specific price trends
- accounting purposes and deflating other series
- inflation targeting by central banks
- cross-country economic comparisons.
The euro area (evolving composition) index is used by the European Central Bank (ECB) as the main indicator for monetary policy management. The ECB and the European Commission's Directorate-General for Economic and Financial Affairs (DG ECFIN) use the HICP for assessing price stability and price convergence required for entry into European Monetary Union.
Other users include: National Central Banks, financial institutions, economic analysts, the media and the public at large.
12.1.1. User Needs - national specifics
The users of the CPI/HICP data are as follows:
- European Commission (Eurostat) uses the data to meet legislative requirements.
- Central Banks e.g. National Central Bank, ECB and other Central Banks use the data for monetary policy development.
- Government Departments e.g. Department of Finance, Department of the Taoiseach (Prime Minister), Department of Public Expenditure & Reform, Department of Social Welfare, Revenue Commissioners use the data for national policy development.
- Economists, Analysts e.g. Economic & Social Research Institute (ESRI) and stockbrokers use the data as a general macroeconomic indicator.
- The Court System uses the data for indexation of court awards e.g. maintenance and disability payments
- Businesses uses the data to help price their products.
- The general public use the data as a general measure of cost of living increases.
One of the recommendations from the National Consumer Price Index Review Group (March 2010) was Recommendation 18.
- The introduction of socioeconomic price indices (including income deciles/quartiles) is considered to be a priority and the CSO should carry out further research in this area.
12.2. Relevance - User Satisfaction
No information.
12.3. Completeness
The full set of HICPs and HICP-CT at ECOICOP 5-digit level, are transmitted to Eurostat each month.
13.1. Accuracy - overall
The accuracy of source data is monitored by assessing the methodological soundness of weight and price sources and the adherence to the methodological recommendations. The Household Budget Survey (HBS) is the main source for weights every five years while National Accounts data is used for annual updating. Local price collection (visits to local retailers and service providers) and central price collection (post, telephone, e-mail and the internet) are the data sources for prices. The items selected for pricing and the method selected for price collection reflect both consumer choice and behaviour. The type of survey and the price collection methods ensure sufficient coverage and timeliness.
13.2. Sampling error
The HICPs are statistical estimates that are subject to sampling errors because they are based on a sample of consumer prices and household expenditures, which are not the complete universe of all prices/expenditures.
Numerical estimates of the HICP sampling errors are not produced by the CSO. The CSO try to reduce sampling errors by using a sample of consumer prices that is as large as possible given resource constraints.
13.3. Non-sampling error
Non-sampling errors are not quantified. The CSO try to reduce non-sampling errors through continuous methodological improvements and survey processing improvements (e.g. a new Electronic Data Capture system was introduced by the CSO for local price collection in 2016).
13.3.1. Coverage error
This information is not available.
13.3.1.1. Coverage error population
All target population is currently covered in the Irish HICP.
13.3.1.2. Coverage error regions
No geographical areas excluded from the sample frame.
14.1. Timeliness
The full set of HICPs is published each month according to a pre-announced schedule, usually between 15 and 18 days after the end of the reference month. Each year, the January news release is published at the end of February to allow for the annual update of the weights of individual product groups and the relative country weights of Members States in the country-group aggregates.
The euro area flash estimate is published on the last working day of the reference month or shortly after that.
14.1.1. Time lag - final result
Periodicity and timeliness of the datasets:
- HICP Flash Estimate (T+0)
- HICP (T+15)
- HICP-CT (T+15)
HICPs are compiled every month. HICP weights are sent to Eurostat annually as per the schedule set out by Eurostat.
The full set of HICPs is published nationally each month according to a pre-announced schedule. Our publication policy is as follows:
- Always publish at least one day previous to Eurostat
- Publish as early as possible in the process but not later than 4 weeks and 2 days after pricing day for all months except February (January reference month).
- In February, publish as early as possible in the process but not later than 6 weeks after pricing day (due to annual updating of the weighs and other annual methodological improvements).
14.1.2. Timeliness of sub-indices
The full set of HICPs at ECOICOP 5-digit level is transmitted each month to Eurostat as per the agreed transmission schedule. The data is transmitted to Eurostat under embargo, if the national CPI publication is scheduled to be published after the deadline for transmission of data to Eurostat.
14.2. Punctuality
Since the March 1997, launch of the HICP release, the HICP for the country groups aggregates has always been published on the pre-announced release dates.
15.1. Comparability - geographical
HICPs across Member States aim to be comparable. Any differences at all levels of detail should only reflect differences in price changes or expenditure patterns.
To this end, concepts and methods have been harmonised by means of legislation. HICPs that deviate from these concepts and methods are deemed comparable if they result in an index that is estimated to differ systematically by less than or equal to 0.1 percentage points on average over one year against the previous year (Article 4 of Council and Parliament Regulation (EU) 2016/792).
15.2. Comparability - over time
HICP data are considered to be comparable over time. There have been several improvements in methodology since HICP was introduced with the aim of improving reliability and comparability of the HICP. These changes may have introduced breaks in time series. However, back calculations under the newer standards were performed when appropriate basic data was available.
15.3. Coherence - cross domain
Differences between the HICP and national CPI
- The following expenditure is included in the HICP but excluded from the national CPI: Games of Chance
- The following expenditure is included in the national CPI but excluded from the HICP: mortgage interest, union subscriptions, motor car tax, motor cycle tax, building materials, motor car insurance (non-service), home insurance - contents (non-service) and home insurance - dwelling.
15.4. Coherence - internal
The HICPs are internally coherent. Higher level aggregations are derived from detailed indices according to well-defined procedures.
Not available.
17.1. Data revision - policy
The HICP series, including back data, is revisable under the terms set in Articles 17-20 of Commission Implementing Regulation (EU) 2020/1148.
17.1.1. Data revision - policy - national specifics
The national CPI is not subject to revision. HICP series, including back data, are revisable under the terms set in Commission Regulation (EC) No 1921/2001 of 28 September 2001 (repealed and replaced by Commission Implementing Regulation (EU) 1148/2020). The published HICP data may be revised for mistakes, new or improved information and changes in the system of harmonised rules.
17.2. Data revision - practice
The HICP back data (HICP and HICP-CT) were revised marginally in 2016 due to the change in methodology for referencing the HICP data to 2015=100 (compared to 2005=100).
The national CPI has never been revised as per the revisions policy.
18.1. Source data
Please see information under the next points.
18.1.1. Weights
National Account t-2 is used as starting point for ECOICOP ver.2 at the 5 digit level. Adjustments to t-2 data is then made using detail available in National Account quarterly data for t-1 Q1-Q3 only. Further adjustments are then made using retail/credit card data to items not identified in quarterly data. This involved multiplying the t-2 value by an indicator of the change in expenditure based on these data sources.
These weights are price updated every December.
Elementary Aggregates propositions are defined by latest HBS. These were adjusted in some cases to reflect previous year.
The HBS data is available in ECOICOP Ver.2.
The HFMCE data from National Accounts is available in ECOICOP Ver.2.
18.1.1.1. Compilation at elementary aggregate level
Weights are generally not adjusted at the elementary aggregate level on an annual basis, however, they the weights at the 4-digit level of ECOICOP are reviewed and updated annually and weights at the 5-digit level are recalculated each year on a pro rata basis using the structure of the most recent Household Budget Survey (HBS).
18.1.1.2. List of elementary aggregates
Restricted from publication
18.1.1.3. Compilation of sub-index weights
National Account t-2 is used as starting point. Adjustments to t-2 data is then made using detail available in National Account quarterly data for t-1 Q1-Q3 only. Further adjustments are then made using retail/credit card data to items not identified in quarterly data. This involved multiplying the t-2 value by an indicator of the change in expenditure based on these data sources.
Adjusted data is then price updated to t-1. Majority of adjustments are made at 4-digit level and proportions remain the same at detail below this based on latest HBS.
National Accounts Annual Expenditures t-2. Adjustments made using NA t-1 quarterly data Q1-Q3 only. Further adjustments using retail/credit card data t-1.
Q1-Q3 are used for adjustments. Q4 is not available in time to be included in the adjustments. The methodology takes the differences between T-2 Q1 and T-1 Q1, T-2 Q2 and T-1 Q2, and T-2 Q3 and T-1 Q3 and gets the average of these differences to estimate a T-1 Q4 value based on the T-2 Q4 value.
18.1.1.4. Price updating
T-2 data is price updated to make the expenditure shares representative of t-1. Price updating is done at an elementary aggregate level. The expenditure shares for the elementary aggregates are adjusted with the price change between year t-1 and December and year T-1.
18.1.2. Prices
Price data is based on Survey data.
18.1.2.1. Prices Data Source - detailed information
Restricted from publication
18.1.2.2. Price collection survey
Restricted from publication
18.1.2.3. Administrative data sources
No administrative data source currently being used in the production of the HICP
18.1.2.4. Transaction data - general information
We currently use 2 sources of scanner data in our HICP calculations. Scanner data was first introduced into the HICP as a response to the COVID-19 pandemic in March 2020 and work is underway to incorporate two more major retailers into the HICP calculations, replacing data collected in store. The aim is to have these last 2 sources of scanner data incorporated into the HICP by the end of 2025.
For more information on the scanner data project, please see the the document 'The Scanner Data Project in CSO', on CSO's website.
18.1.2.5. Web scraping - general information
Webscraping was introduced during the pandemic (March 2020) as a proxy for physical in store price collection which was stopped due to COVID-19. Automated web-scrappers were set up for supermarkets and certain multi-item stores. Manual web-scraping is carried out by staff centrally in the CSO for hardware and clothing and footwear items. At the time of the introduction of web-scraped data into the HICP, some spot check was done on known popular items to assess the coherency of the web-scraped data with items that were priced in-store.
Automated scrapers are no longer used for the compilation of the HICP due to the provision of transaction data by the supermarkets and the closure of some multi-item stores in the last 2 to 3 years.
At this time no foreign websites are scraped, work is underway to assess the suitability of pricing from non-Irish domained online stores.
18.1.3. Sampling
See information under the next points.
18.1.3.1. Sampling design - locations for survey
To ensure the State is fully represented, the country is divided into 8 Nomenclature of Territorial Units for Statistics 3 (NUTS 3) regions. The regions are combined into 5 areas: Dublin; South-West; Border, Midland and West; Mid-West and Mid-East and South-East regions.
Purposive (or judgmental) sampling is then applied, whereby Dublin and the regional cities (Cork, Limerick, Waterford and Galway) are automatically included in the sample while a sample of towns (locations) are selected from the remaining strata with the constraining factor that each county in the State must be represented. As of December 2023, there are approximately 30 cities and towns in the HICP sample of locations.
18.1.3.2. Sampling design - outlets
Outlets are selected for both central price collection and local price collection in similar ways.
A purposive sampling approach is applied to select the sample of retail outlets within a location (i.e. retail outlets are chosen which are the most popular). These are selected mainly by office-based staff. However, local knowledge is also supplied by the price collectors in the field.
Scanner data is also received from 4 of the 5 major supermarket retailers in Ireland.
Central price collection is typically used where national pricing applies (e.g. health insurance), or where local price collection would not be suitable. There are 137 item headings for which prices are collected centrally through postal, e-mail, telephone enquiries along with internet price collection. Of these 129 item headings are used in the compilation of the HICP.
18.2. Frequency of data collection
Price data is collected every month.
18.3. Data collection
See information under the next points.
18.3.1. Timing of price collection
The reference day for pricing was the second Tuesday of each month up to 2010. Since February 2010, prices are collected over a period of more than one working week, i.e. Monday prior to the second Tuesday of the month up to and including the third Tuesday of the month. This was necessary to meet the requirements of Council Regulation (EC) No. 701/2006 regarding the temporal coverage of price collection in the Harmonised Indices of Consumer Prices (HICP) (repealed and replaced by Commission Implementing Regulation (EU) 1148/2020).
Similar to other products in the basket, the prices for energy products and fresh fruit and vegetables are collected over the period of more than one working week.
18.3.2. Devices for price collection
For pricing locally in stores across the country a specifically designed smartphone application is used. This is called Formation and is an android application.
Computers are used for internet online prices.
This software has some built in edit checks and further edits are carried out by office staff on return.
18.4. Data validation
Controls on quality of the data
Prices are collected with detailed product descriptions and indicators of sales, multiple offers etc. The prices returned are initially scrutinised, visually checked and finally edited (both micro- and macro-edits are applied, checking price ratios for individual items, elementary aggregates and higher levels of aggregation).
18.4.1. Data validation - Survey data
Data Checks
The most important data check is price change. The price recorded is compared (i.e. validated) with the price for the same product in the same retail outlet in the previous month. Prices outside the relevant price range (outliers, unexpected price changes etc.) are re-checked by CPI staff to determine inclusion or exclusion for the purpose of the HICP compilation for that month.
Once the price data is correct and complete, preliminary item indices are calculated using the prices, which passed the data checks, plus those that have been manually accepted. These preliminary item indices are in turn checked to ensure price changes have been correctly reflected in the calculations.
Both micro- and macro-edits are applied, checking price ratios for individual items, elementary aggregates and higher levels of aggregation.
Data Collection - Field audits
To check that price collections are carried out correctly, CPI personnel carry out monthly quality audits on individual local price collections. There are two types of quality audits. The first involves an auditor accompanying a price collector on a price collection. The second consists of audits, which take place no later than three days after the price collection (back check), where an auditor repeats the price collection to determine if the price collector has collected the correct prices. Multiple locations are visited each month and price collectors do not know in advance which locations will be chosen for the quality control checks.
Data Collection – Central Price Collection
CPI headquarters staff manually enters data collected from service providers (via post, e-mail and telephone enquiries along with internet price collection) into Excel files. Any implausible or erroneous data highlighted after the above data checks is validated by requesting confirmation from the retail outlet or service provider. If confirmation, is not received the price is removed from the calculations.
Generally, extreme price changes are accepted unless the price change is considered implausible by the CPI section staff. If the price change was considered implausible, the price would be queried with the respondent and treated as estimated until a correct or revised figure is supplied.
When prices are recovering from sales, generally, we would accept the price recoveries even if the price was substantially greater than the pre-sale prices. Exceptions apply here for electronic goods. A recovery price is accepted only 20% greater than the original pre-sale price for electronic goods.
Aggregation and Compilation
There are detailed procedural notes for the compilation of the HICP using the statistical software package of SAS. Within these procedures, a system of 'quality gates' is used. This ensures that certain checks are completed systemically at each stage of the compilation before it is possible to move onto the next stage of compilation. For example, when the prices are being imported into SAS from the SQL database, an output file is produced analysing the number of prices collected for each item in the basket. If the number of prices is implausible, then further investigation must take place.
Dissemination
The dissemination process has been automated in SAS to reduce the human input to the minimum. Again, this process is controlled through a set of detailed procedures using a system of 'quality gates' similar to that described for aggregation and compilation. The security of the folder(s) used for dissemination are also tightly monitored with IT using access controls.
18.4.2. Data validation - transaction data, web scraping and large administrative data
For transaction data, an R-Shiny app allows for quick analysis of each retailers transaction once it is brought in for use in the HICP calculations. This app flags outliers in the transaction data quickly and allows for the data to be queried with the retailer if necessary.
Automated checks also occur for the manually webscraped data, however issues with this data is less likely as the manual scraping is done by experienced staff.
18.4.3. Data validation - weights
Weights are compared to previous years weights to check if there have been significant changes to any 4 digit ECOICOP Ver.2 weight. Any potential errors are queried with colleague in National Accounts to confirm the reasoning for the weight changes year on year.
18.4.4. Indices
Indices are checked during and at the end of the HICP production cycle by section staff and section statistician.
The development of sub-indices over time is also analysed to check the trend of the indices is matching up to what is expected or against other European Member States
18.5. Data compilation
The HICP is a Laspyeres-type index
Jevons price index (ratio of geometric means) is used for the elementary aggregate formulae.
For price observations, 2 decimal places (to the cent) are used. Weights are defined up to 0.001 parts per thousand.. Indices and rates of change are compiled at 12 decimal places and transmitted to Eurostat at 12 decimal places. Figures are published on the CSO website at 1 decimal place.
The calculation of the entire back series data fro ECOICOP Ver.2 was done using reallocation of elementary aggregates.
There has been no use of annual linking methods in January 2026.
Games of chance has been included in the HICP from January 2026, covering lottery and scratch-cards ECOICOP Ver.2 09.4.7.0. There is no coverage of online gambling at the moment. Work is underway to improve the data sources to allow the collection of online gambling data.
18.5.1. Elementary price index formulae
The HICP is a Laspeyres-type index. Jevons price index (ratio of geometric means) is used for the elementary aggregate formulae.
We use two decimal places for regular price observations. Weights are defined up to 0.001 parts per thousand. Indices and rates of change are compiled at 12 decimal places and transmitted to Eurostat at 12 decimal places. Index figures and rates of change are published with one decimal place. We apply rounding on the indices before publishing. Rates of change are compiled using rounded indices.
18.5.2. Aggregation of different data sources
The first step of the calculation process for the 478 directly priced item headings is the calculation of source average prices. These sources are as follows:
- Field Pricing
- Prices collected online in the CSO offices
- Different Scanner/Transaction Data providers
A source average price is calculated as the geometric mean of the prices by source of the data, e.g. the average price for 1 litre of low fat milk from one retailer is the geometric mean of the prices for 1 litre of low fat milk collected in the scanner data from that retailer for the month The area source price is technically known as an elementary aggregate as it is the lowest level of calculation within the CPI. Each month, an source average price is calculated both for the current month and the previous month based only on matched price observations between the two periods.
For the remaining items collected centrally, these are not aggregated at area/regional level.
MS Excel can be used at data collection but not during aggregation. Output for transmission to Eurostat is output in text files.
18.5.3. Chaining, linking and splicing methods
From a weights perspective, indices in year y are based in December of year y-1. The resulting indices are chained using the December month as the chain link
18.5.4. Quality adjustments and replacements
See information under the next points.
18.5.4.1. Quality adjustment - detailed information
When a product-offer becomes unavailable due to being discontinued or for another reason, or we get non-response on the product-offer for a prolonged period of time, we can determine that the product-offer requires to be replaced.
Whenever a product has to be replaced by another product, some statistical adjustment has to be made in order to link the price indices and create continuous price series. In principle, this situation may happen for any product covered in the HICP.
Direct Comparison is the most commonly used method of quality adjustment. Bridged overlap is used in situation where direct comparison isn't possible. The bridged overlap method consists in estimating a price development between the replaced product and the replacement product which is equal to the actual average price development (geometric mean) observed for the products belonging to the same consumption segment. This calculation is made with the pre-sale price of the replaced product offer.
Computers and Computer Accessories – Hedonic regression is now used for quality adjustment of replacements.
Package Holidays - Clear guidelines for replacements are now in place. These allow for direct comparison to be used for all replacements.
Scanner Data - Monthly Chaining and Replenishment is used for quality adjustment.
18.5.4.2. Replacements - detailed information
The replacement of a product-offer is based on the following criteria:
The new product-offer should have similar characteristics and be representative as the replaced product-offer (same consumption segment). The concept of consumption segments is used when a product is no longer available and a replacement needs to be found. A replacement product is chosen that is comparable and fulfils the same consumption purpose. This is an implicit use of the concept of consumption segments.
The new product-offer should be representative of what is being sold
The new product-offer should be available for purchase in the subsequent months.
The replacement is made by price collectors for local price collections and by office staff for central price collection. A replacement product is sought generally after no more than two months.
18.5.5. Administered prices
The classification of administered prices is updated on an annual basis. See information below on COICOP categories which are administered and the changes that occurred over the last number of years:
- Fully administered: 04.42 (up to December 2006)
- Mainly administered: 04.41 (from January 2015); 04.43 (from January 2015); 04.51(up to December 2011); 04.52 (up to December 2014); 06.30; 07.31 (from January 2011); 07.32; 07.35 (from January 2011); 08.10; 12.53 (up to December 2008)
There are no prices which are directly set by government but some prices are influenced by government generally through the regulator for that market.
Some recent changes include the domestic retail gas market in Ireland was fully deregulated in July 2014 and water supply and sewage disposal charges were introduced in January 2015. Irish Water must apply to the Commission for Energy Regulation (CER) for approval for any changes to the price charged to domestic customers for water services. Separately, the Government has put in place a cap (through legislation) on the amount that can be charged to customers until the end of 2016. There is a current suspension of water and sewage charges in Ireland.
18.5.6. HICP at constant tax rates
HICP-CT is produced in line with methodology as described in the manual. Series are available at the same time as HICP headline series. Changes in tax rates are included in the HICP-CT from the month where tax rates change.
For each product, current taxes are subtracted and the equivalent base period taxes are added. Aggregation follows the same methods as the regular HICP. Tax changes are added to the next full month after the tax change occurs.
There are primarily four rates of VAT, depending on the goods or service. The rates are:
- standard rate: 23 percent
- reduced rate: 13.5 percent
- second reduced rate: 9 percent
- zero rate: 0 percent
The standard rate of VAT applies to most goods and services, however certain goods and services are liable for reduced rates or exempt for VAT
Tobacco products are treated the same as all other product in that Tax changes are added to the next full month after the tax change occurs.
18.5.7. HICP flash estimate
The flash estimate for HICP is run to meet the published Eurostat deadline. The CSO publishes limited results from the Flash Estimates of HICP on the day before the publication day of Eurostat.
If a price relative for a particular item is not available when the flash estimate is run then that price relative must be imputed using various techniques. These are outlined below.
Within Group Imputation
This is the most common method of estimation for the price relatives. Almost all of the items in the basket have been amalgamated into imputation groups. The remaining six items are imputed using a different method outlined below. These groups were devised using two, three or four digit COICOP. The level at which the groups were formed depended specifically on the items in question.
If a price relative is missing within one of the imputation groups, then a weighted average of the remaining price relatives within that group is calculated and applied to the missing item. The assumption is that the missing price relative potentially has a similar price movement for that month as other price relatives within the imputation group.
All Relatives – Missing Group
This would be an unusual case but could possibly occur if for some reason all price relatives were missing within an imputation group. In this case, the estimated price relative is calculated as a weighted average of all available price relatives in the basket. By taking this approach, the missing price relatives do not affect the overall estimated inflation rate.
All Relatives - Special Case
There were four items in the basket where it was felt that the imputation group method was not appropriate. These were:
- Private rents
- Local authority rents
- Mortgage interest
- Package holidays
In these cases, the estimated price relatives are calculated as a weighted average of all available price relatives in the basket. By taking this approach, the missing price relatives do not affect the overall estimated inflation rate.
Impute Relative = 1
This used for Water Supply and Sewage Charges.
18.5.8. Other quality and processing issues
Detailed Below
18.5.8.1. Missing prices
Price collectors are required to record on their electronic devices if there are any special features associated with the price observations. These are known as indication codes. Code 8 (item is temporarily unavailable) and 9 (item is not available in this area) cover items that are missing in a particular month.
The general rule for code 8 or 9 is that the price collector is asked to replace the product as soon as it becomes obvious that the product is permanently missing. This is not always possible for particular items in some rural areas or small towns. In that case, prices are estimated for 2 months and if the product-offer does not return then a replacement is found.
In the case of clothing and footwear, marginally different rules apply. For code 8 or 9, the last observed price is used as an estimate for three consecutive months. If the item does not reappear, the item will be deemed permanently missing and be replaced.
The number of missing prices can be calculated by analysing the number of code 8s or 9s in a particular month.
The price recorded is compared (i.e. validated) with the price for the same product in the same retail outlet in the previous month. Prices outside the relevant price range are checked by CPI staff to determine inclusion or exclusion for the purpose of the CPI compilation for that month.
18.5.8.2. Sales and discounts
The prices used in calculating the HICP are those actually paid by households. The Commission Regulation No 2602/2000 on price reductions has been implemented (repealed and replaced by Commission Implementing Regulation (EU) 1148/2020). No revisions were required in the index.
The following guidelines (or principals) are applied to the Irish HICP:
- The HICP reflects the observed cash price for goods and services;
- The main form of restricted discount in store is as a result of holding store specific discount card. For these retailers we are able to calculate a unit price based on the scanner data (inclusive of items bought under discount).
- Other forms of discount are rebates for money off the total value of the shop. These are not included in the HICP as they aren't linked to a single product.
- For other types of pricing (non-grocery) we still take the observed price unless the discount is clearly available to everyone as determining the share of discounted prices is too difficult.
- Free gifts/extras such as plastic toys in cereal boxes, ‘send in 20 tokens for a free pen’ and trading stamps are ignored; they are regarded as extras, which may not be wanted by consumers.
- Sale prices are recorded if they are temporary reductions on goods likely to be available again at normal prices or end of season reductions. Prices in closing down sales and for special purchases of end of range, damaged, shop soiled or defective goods are not recorded as they are deemed not to be of the same quality as or comparable with, goods previously priced or those likely to be available in future.
18.5.9. Specific product groups
Please see information under the next points.
18.5.9.1. Seasonal items
Currently there are no seasonal products included in the basket for HICP.
18.5.10. Classification change
Calculation of the back series for ECOICOP Ver.2 is based on reallocation of elementary aggregates.
There is no impact on the All-Items HICP. The All-Items HICP (00) is aggregated of the elementary aggregates so there is no impact as the weights and indices were just reallocated.
At a 2-digit level, there is no impact on the ECOICOP groups:
- 01 - Food and Non-Alcoholic Beverages
- 02 - Alcoholic Beverages, Tobacco and Narcotics
- 06 - Health
- 10 - Education
- 11 - Restaurants and Accomodation Services
(The impact of ECOICOP Ver. 2 Group 12 - Insurance and Financial Services cannot be assessed as it is a new category)
In terms of weights, based on data from 2025, the following Groups have changed by:
- 03 - Clothing and footwear: -0.8%
- 04 - Housing, Water, Electricity, Gas and other fuels: +0.4%
- 05 - Furnishings, Household Equipment and Routine household maintentance: -1.0%
- 07 - Transport: +1.3%
- 08 - Information and Communications: +65.6%
- 09 - Recreation, Sport and Culture: -21.6%
In terms of Indices, based on December 2025 data the change in classification has the following impact:
- 03 - Clothing and footwear: 0.0%
- 04 - Housing, Water, Electricity, Gas and other fuels: -0.1%
- 05 - Furnishings, Household Equipment and Routine household maintentance: 0.0%
- 07 - Transport: +0.1%
- 08 - Information and Communications: -0.5%%
- 09 - Recreation, Sport and Culture: +0.8%
18.6. Adjustment
Please see the information under the next point.
18.6.1. Seasonal adjustment
The HICP is not seasonally adjusted.
None.
The harmonised index of consumer prices (HICP) is a consumer price index (CPI) that is calculated according to a harmonised approach. It measures the change over time of the prices of consumer goods and services acquired by households (inflation).
Due to the common methodology, the HICPs of the countries and European aggregates can be directly compared.
2 February 2026
The main statistical variables are price indices. There are no discrepencies from the European Statistical System standards.
The basic unit of statistical observation are prices for consumer products.
Please see the information under the next points.
Please see the information under the next point.
HICP is a monthly statistics.
The accuracy of source data is monitored by assessing the methodological soundness of weight and price sources and the adherence to the methodological recommendations. The Household Budget Survey (HBS) is the main source for weights every five years while National Accounts data is used for annual updating. Local price collection (visits to local retailers and service providers) and central price collection (post, telephone, e-mail and the internet) are the data sources for prices. The items selected for pricing and the method selected for price collection reflect both consumer choice and behaviour. The type of survey and the price collection methods ensure sufficient coverage and timeliness.
The following units are used:
- Index point
- Percentage change on the same period of the previous year (rates);
- Percentage change on the previous period (rates);
- Percentage share of the total (weights).
The HICP is a Laspyeres-type index
Jevons price index (ratio of geometric means) is used for the elementary aggregate formulae.
For price observations, 2 decimal places (to the cent) are used. Weights are defined up to 0.001 parts per thousand.. Indices and rates of change are compiled at 12 decimal places and transmitted to Eurostat at 12 decimal places. Figures are published on the CSO website at 1 decimal place.
The calculation of the entire back series data fro ECOICOP Ver.2 was done using reallocation of elementary aggregates.
There has been no use of annual linking methods in January 2026.
Games of chance has been included in the HICP from January 2026, covering lottery and scratch-cards ECOICOP Ver.2 09.4.7.0. There is no coverage of online gambling at the moment. Work is underway to improve the data sources to allow the collection of online gambling data.
Please see information under the next points.
Monthly.
The full set of HICPs is published each month according to a pre-announced schedule, usually between 15 and 18 days after the end of the reference month. Each year, the January news release is published at the end of February to allow for the annual update of the weights of individual product groups and the relative country weights of Members States in the country-group aggregates.
The euro area flash estimate is published on the last working day of the reference month or shortly after that.
HICPs across Member States aim to be comparable. Any differences at all levels of detail should only reflect differences in price changes or expenditure patterns.
To this end, concepts and methods have been harmonised by means of legislation. HICPs that deviate from these concepts and methods are deemed comparable if they result in an index that is estimated to differ systematically by less than or equal to 0.1 percentage points on average over one year against the previous year (Article 4 of Council and Parliament Regulation (EU) 2016/792).
HICP data are considered to be comparable over time. There have been several improvements in methodology since HICP was introduced with the aim of improving reliability and comparability of the HICP. These changes may have introduced breaks in time series. However, back calculations under the newer standards were performed when appropriate basic data was available.
