The UK House of Commons Library has published a guide on local migration data, setting out which statistical sources can tell policymakers, researchers and local authorities how many migrants live and work in specific areas of the United Kingdom.

The guide, available on commonslibrary.parliament.uk, responds to a recurring problem: most official migration statistics in the UK are produced at national level, while decisions on housing, school places, health services and local integration programmes depend on numbers for towns, cities and regions. The Commons Library briefing brings together the datasets that partially fill this gap and explains what each one can and cannot show.

The Office for National Statistics (ONS) remains the backbone of the UK's migration statistics. Its long-term international migration estimates, based on the reworked methods introduced after the closure of the International Passenger Survey, provide the headline figures for immigration, emigration and net migration. These estimates, however, are designed for the whole of the UK and for broad breakdowns, not for individual local authorities.

For local-level insight, the guide points users to administrative data. The census remains the most comprehensive source, capturing country of birth and passports held for every household in England and Wales. Census outputs allow users to compare migrant populations across local authority districts, though the picture is necessarily several years old between census cycles.

Population estimates produced by the ONS add annual updates between census years. They include area-level figures broken down by country of birth and nationality, giving councils and service planners a more current, if less detailed, view of how local migrant populations are changing.

The briefing also covers the Migration Advisory Committee (MAC), which advises the government on the immigration system and publishes data relevant to its work on shortage occupations and salary thresholds. MAC analysis draws on national datasets and helps inform decisions that later affect local labour markets, even when its published figures are not local themselves.

Home Office administrative data forms another strand. Visa grants, asylum applications and resettlement figures are recorded when individuals interact with the immigration system. These datasets can be aggregated by the local authority where a visa holder or asylum seeker lives or is dispersed, giving a direct — if partial — count of recent migration flows at local level. Local authority-level asylum dispersal data, for example, shows where people receiving asylum support are accommodated.

Department for Work and Pensions records add a labour market dimension. National Insurance number registrations to adult overseas nationals entering the UK are recorded by the location of registration, offering a proxy for where working-age migrants first settle. The Commons Library guide flags the known limitations of this measure: registration location does not always equal residence, and the data covers only those who register for a National Insurance number.

For readers trying to track migration at the level of parliamentary constituencies, the Library points to its own constituency-level statistics, which translate census and administrative data into the geography that MPs and their staff most often work with.

The guide's practical message is that no single dataset answers the question "how many migrants live in my area?" Each source measures something different: a stock of people born abroad, a flow of new visa holders, a count of National Insurance registrations, an asylum dispersal placement. Users must combine sources and apply the caveats attached to each.

The Commons Library publishes such briefings to support MPs and the public with impartial research. The full guide, including links to each dataset and explanations of coverage and methodology, is available on the Commons Library pages of the UK Parliament website. Readers seeking figures for a specific area should consult the ONS and Home Office publication pages directly, since each dataset carries its own release schedule and geographical coverage.