This dataset provides 2011 Census estimates of the usual resident population of the UK who were living at a different address one year ago. The data classifies people currently resident in each local authority or higher area in the UK by age and by sex and shows which local authority or higher area in the UK they were resident in one year before the Census. The estimates are as at census day, 27 March 2011. People resident outside of the UK one year before the census are counted in the category 'Outside UK'.

In order to protect against disclosure of personal information from the 2011 Census, there has been swapping of records in the Census database between different geographic areas, and so some counts will be affected. In the main, the greatest effects will be at the lowest geographies, since the record swapping is targeted towards those households with unusual characteristics in small areas.

More details on the ONS Census disclosure control strategy may be found on the Statistical Disclosure Control page on the ONS web site.