After the adoption, of the EU Climate and Energy Package (2008), the European Commission launched the Covenant of Mayors (CoM) to endorse and support the efforts deployed by local authorities in the implementation of sustainable energy policies. Nowadays the CoM is the mainstream European movement involving local and regional authorities, voluntarily committing to meet and exceed the European Union 20% CO2 reduction objective by 2020. Up to mid-March 2013, 5?049 municipalities, representing 160 million citizens in EU and 27 from outside, signed the Covenant of Mayors (CoM). A key document, showing how to reach the emission reduction is the Sustainable Energy Action Plan (SEAP) that is submitted by the local authority together with a Baseline Emission Inventory (BEI). It identifies the sectors of human activity and emission abatement measures that are furtheron yearly monitored and compared with the reduction target. The SEAP covers mainly the CO2 emissions that occur due to energy consumption in the territory and under the responsibility of the local authority (excluding industries). Examples of actions are the development of the district heating network, wind farms and solar photovoltaic installation, but also wastewater and solid waste treatment with methane recovery. CoM authorities may decide to account emissions using either a standard or a LCA approach. The two approaches have common activity data but different emission factors (EF) for each energy carrier, for which national defaults are provided in the CoM Guidebook. Whereas the IPCC standard yields an amount of emissions related to the carbon content of the vector, the LCA approach produces a more holistic amount of emissions that is related to the whole fuel supply-chain that is characterised by the European reference Life Cycle Database (ELCD). Practicaly, the different system boundaries of the two approaches are included in the application of different EFs. We analysed statistically a sample of 1?278 SEAPs (representative for 50 million EU citizens) that are accepted by 11/06/2013 and that did not show outlayer values. The LCA approach is used much less (by 76 authorities out of the 1?278) than the standard IPCC approach. In order to promote the LCA approach, a comparison with IPCC approach and analysis of benefits and drawbacks is needed. The SEAPs setup under LCA approach include on average less actions than the plans using IPCC approach (42 versus 47) and a smaller total emission reduction (85 ktCO2-eq versus 100 ktCO2-eq). Nevertheless the average reduction estimation per action for SEAPs using LCA is larger than for plans using IPCC (3600 tCO2-eq/action versus 2000 tCO2-eq/action). Among other aspects, also the share of sectors in SEAPs differs. Plans with LCA approach include more actions in non-energy-related emission sectors, such as waste managements, and in sectors with local electricity production and local district heating. In general terms, actions in SEAPs planned using an LCA approach lead to a more holistic accounting of emission reduction but they remain more complex to understand and prepare by the local authorities. Extra effort on specific database for SEAPs using LCA is worth to be envisaged in order to facilitate the use of such method. Furthermore the LCA approach resulted particulary fitted for Southern countries (see the involment in the CoM of countries from Magreb and Masrik regions) with more potential in non-energy-related sectors.