About this data

Source: Home Office, Irregular migration to the UK, year ending June 2026 (IER_D01); ONS, Long-term international migration, provisional: year ending December 2025

• Small boat arrivals each calendar year divided by ONS's estimate of total immigration: people moving to the UK for at least 12 months, from anywhere, by any route.
• The two are counted differently. ONS counts people who stay for at least a year; the Home Office counts everyone detected arriving on a small boat. Most small boat arrivals claim asylum and stay, so most are also counted in ONS's immigration figures, but the share is an approximate comparison.
• The share depends on total immigration as well as on small boats: part of the rise in 2025 is because overall immigration fell.

This chart appears in Migration.