What is the annual cost of supporting illegal immigrants in the UK?
Executive summary
Estimates of the annual cost of supporting “illegal immigrants” in the UK vary widely because commentators and official bodies use different definitions, time‑periods and cost categories; headline figures in recent reporting range from about £1.3 billion to over £11 billion depending on methodology [1] [2]. The most robust government and audit outputs for 2023–24 put asylum and migration spending in the low single‑digit billions (roughly £3–£5bn), but analysts and think‑tanks flag large in‑year pressures and contested assumptions that could raise projected costs substantially [3] [4] [5].
1. The near‑term published totals: government and NAO snapshots
Home Office and parliamentary figures reported in 2023–24 and cited in Parliament show asylum costs in the order of £3–4bn for recent years, with Home Office numbers quoted at £3.96bn for the year up to 2023 and NAO‑based reporting saying around £4.7bn was spent on asylum support in 2023–24 [3] [4]. These are the closest available official headline figures for “asylum and migration” cashflows; they capture accommodation, casework and some operational costs but are not a single comprehensive auditor’s tally of every downstream public‑service impact [4] [6].
2. Wider fiscal pressures and contested projections
Independent fiscal analysts and Treasury audits identify much larger “spending pressures” on top of planned budgets: Rachel Reeves’s audit and the IFS highlight an estimated £6.4bn of asylum and illegal migration pressures in 2024–25 once in‑year overspends and one‑off items are counted [5]. The Home Office’s own earlier impact assessment warned that, if current trends continued without policy change, accommodation costs might climb to about £11bn a year by 2026 — a projection that has been politically weaponised and publicly disputed for its assumptions [2].
3. Lower‑end and advocacy figures: methodology matters
Outside government, charities and campaign groups produce sharply different totals by narrowing or widening what they include; MigrationWatch’s calculation focused on accommodation bills for a subset of claimants produced a lower headline of roughly £1.3bn annually, a figure that depends on selecting particular cohorts and cost lines [1]. Conversely, the Migration Observatory and others show how per‑person daily assumptions (for example, £85/day for accommodation used in some assessments) translate into per‑head annual costs of around £31,000 if sustained long‑term — demonstrating how choice of per‑day rates and lengths of stay explodes the headline totals [7].
4. Hidden costs, aid accounting and sectoral knock‑on effects
Some spending reported against “asylum” appears in unusual places: the Foreign, Commonwealth & Development Office’s in‑donor refugee accounting and ICAI reporting trace billions of pounds of UK aid redirected to hosting refugees domestically — about £4.3bn reported in 2023 — which complicates straight‑line comparisons between Home Office budgets and total public spending on displaced people [8]. Parliamentarians have also highlighted nearly £8 million a day in housing costs and the disproportionate share of hotel bills in particular years, which help explain why headline totals jump year‑on‑year [3] [9].
5. Disputed narratives and political incentives
Numbers are politically freighted: ministers and opponents use worst‑case forecasts to argue for policy shifts (the Illegal Migration Act debate) while advocacy groups stress humanitarian obligations and audit‑value concerns [2] [8]. Select sources make simplifying claims — for example, viral social posts claiming “£1 billion a month” for hotels — that fact‑checks have debunked, underscoring how misinformation amplifies crude totals outside their proper context [10]. Migration‑focused think tanks and MPs have explicit agendas (restrictive control versus protection and rights), so their estimates must be read against those objectives [1] [3].
6. Bottom line and caveats
The best available consolidated figures place recent annual asylum‑and‑migration spending in the low‑to‑mid single billions (c. £3–5bn in 2023–24), with fiscal auditors and analysts warning of higher in‑year pressures (c. £6.4bn) and scenario projections that could reach much larger sums if current trends continued (up to £11bn in some 2026 scenarios) — all depending on which costs are counted and what assumptions are made about numbers, accommodation types and removals [4] [5] [2]. Precise attribution to “illegal immigrants” is limited by data: many sources aggregate asylum seekers, refugees and related migration spending, and none of the provided documents delivers a single uncontested, fully‑itemised national figure for strictly “illegal immigrants” alone [4] [6].