When Ireland introduced the Old Age Pension in 1908 many applicants had no birth certificate as Civil Registration did not begin until 1864. So the 1841 and 1851 census returns were used to prove age. This commercial site has a database to the Old Age Pension Claim Forms held in the Public Records Office of Northern Ireland covering Antrim, Armagh, Down, Fermanagh, Londonderry and Tyrone. Information from similar records (Census Search Forms), held by the National Archives in Dublin are being progressively added to this database. Searches are free but you do need to pay (£2 each) to view records found.