This dataset classifies the usual resident population of England and Wales as at census day, 27 March 2011, by passports held, by sex and by age.

This dataset counts each person only once, therefore people only appear in one category even if they hold more than one passport.

In cases where a person recorded having more than one passport, they were categorised in the following priority order: 1. UK passport, 2. Irish passport, 3. Other passport

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 http://www.ons.gov.uk/ons/guide-method/census/2011/census-data/2011-census-prospectus/new-developments-for-2011-census-results/statistical-disclosure-control/index.html[Statistical Disclosure Control] page on the ONS web site.