Methods used in Scotland and Northern Ireland are broadly similar.
UK estimates are made by adding together estimates for England, Wales, Scotland and Northern Ireland. Members of the US armed forces stationed in England and Wales are included at their place of residence. Students are taken to be resident at their term-time address. Prisoners are regarded as usually resident at an institution if they have served 6 months or more of a custodial sentence. For any group of the population where the concept of 'usual resident' is not easy to define, the definitions used in the 1991 Census of Population are carried through into the population estimates.