These were introduced by the 2003 reform of the Common Agricultural Policy to implement the single payment scheme. Payment entitlements were distributed to farmers based on historical data (at regional or individual farmer level). Following the 2003 reform, to qualify for a single payment, a farmer had to activate the payment entitlements that he or she held together with the same number of eligible agricultural hectares. The 2013 reform replaced these payment entitlements with newly-established payment entitlements under the basic payment scheme. By derogation, some member states respecting certain conditions may keep existing payment entitlements.