The number of new National Insurance Numbers (NINOs) registered by migrants in the UK provides an indication of the number of economically active foreign nationals entering the UK.
New NINOs are issued to all non-UK nationals aged 16 or over working, planning to work legally or claiming benefits in the UK, regardless of how long individuals intend to stay. These statistics are managed by the Department of Works and Pensions (DWP). The DWP makes available data on the NINO allocations to overseas nationals via its online cross-tabulation system. Statistics can be compiled by age, gender, nationality, world area of origin, and a range of territorial units (GORs, Local Authorities and Parliamentary Constituencies). Data are available from January 2002 by calendar and financial year of registration. The DWP also produces an analytical report and summary tables.
There is no information on the length-of-stay, no requirement to de-register when leaving the country, and NINOs do not expire, so this source does not capture out-migration.
Cumulated flows are not a reliable measure of the stock of migrants working in the country at a specific point in time because of the temporary nature of much recent immigration.
NINO records take no account of the length of time spent in employment during the year.
Data refer to year of registration, not year of arrival in the UK and there may be a significant delay between the two events.
Migrants who already have an existing National Insurance Number (for example returning UK nationals or foreigners who have already worked in the UK) are not counted.
There is no indication of internal movements within the UK.