Few political subjects suffer more from category confusion than immigration.
Four phrases are routinely used as though they describe the same group:
immigrants
asylum seekers
people arriving illegally
small-boat arrivals
They do not.
Long-term immigration is much broader
ONS long-term migration statistics measure people changing their country of usual residence for at least 12 months.
The provisional estimate for the year ending December 2025 was 813,000 long-term immigrants and 642,000 emigrants, producing net migration of 171,000.
Most long-term immigration therefore has nothing to do with small boats.
People arrive for study, work, family, humanitarian reasons and other routes.
Asylum is a legal claim for protection
An asylum seeker is somebody asking the UK to recognise that they need protection.
They may have arrived by a small boat, another illegal entry route, a visa, or another route.
Home Office statistics for the year ending March 2026 show that 42% of asylum seekers had arrived by small boat, while 39% had previously entered on a visa or other leave.
So asylum seeker does not mean small-boat arrival.
Most small-boat arrivals claim asylum
The reverse overlap is much stronger.
Home Office data show that since 2018 around 95% of small-boat arrivals have claimed asylum.
But a claim is not the same as a successful claim, and an unresolved claim is not the same as a final refusal.
Among small-boat asylum claims from arrivals through December 2025 that had received an initial substantive decision, Home Office data record both grants and refusals.
Why terminology matters
If a post says “800,000 illegal migrants entered Britain” and uses an ONS immigration figure, it is not simply using a dramatic synonym.
It is changing the category being measured.
Likewise, using the total number of asylum seekers as though all arrived by small boat misstates the data.
Political arguments can still be made about the size of legal migration, asylum policy or Channel crossings.
But they should be arguments about the actual population being discussed.
A simple rule
When somebody gives you a migration number, ask:
Which dataset? Which route? Which legal status? Which time period? Is it immigration, emigration or net migration?
If those questions cannot be answered, the number probably tells you less than the post suggests.