UK net migration could hit 300k by decade’s end, but projections rise.

Net migration to the UK has fallen sharply from last year’s record highs, but official forecasts still point to levels staying above 300,000 later in the decade, complicating Labour’s promise to bring numbers down. Claims that a government adviser expects net migration to rise only to 300,000 by the end of the decade do not match the main official projections.

The Office for Budget Responsibility (OBR), the government’s independent fiscal watchdog, says net migration is on course to reach 340,000 by 2030, even after Home Secretary Shabana Mahmood’s recent visa tightening. Debate is set to intensify before the next budget.

OBR forecast and short‑term trajectory

In its latest forecast update dated November 26, 2025, the OBR said net migration is likely to dip first and then climb again as more migrants stay longer under the post‑Brexit immigration system.

• The OBR expects net migration to fall to a low of 262,000 for the year to mid‑2026 — close to the pre‑Brexit range of 200,000 to 250,000.
• It then expects net migration to rise to 327,000 in 2029 and to 340,000 by 2030.

The OBR links the later rise to higher “stay rates” — meaning people who arrive for work or study are less likely to leave than earlier models assumed.

The “stay longer” pattern and the “Boriswave” effect

That pattern of people remaining longer has been nicknamed the “Boriswave” effect by some analysts, shorthand for how post‑Brexit visas changed who can come and how long they can remain.

• Under the old free movement system, many EU citizens moved in and out of the UK for work in ways that were hard to track.
• The newer visa‑based system for non‑EU nationals produces clearer entries and exits data — and a surprise: people are staying in the UK at higher rates than forecasters first expected.

ONS projection and population impact

The Office for National Statistics (ONS) paints a similar long‑run picture.

• Its principal projection assumes net migration will level off at 340,000 per year from the year ending June 2028 onward.
• This is up from 315,000 in its January 2024 projection.

The ONS says this would drive projected population growth of 6.6 million people to 2037, with net migration accounting for 104% of that growth. The ONS publishes its migration releases ONS publishes its migration releases here.

Short‑term estimates and the changing mix

The forecasts sit alongside a very different short‑term picture.

• Provisional ONS estimates for the year ending June 2025 put net migration at 204,000, down 78% from a peak of over 900,000 in the year ending June 2023.
• Total immigration in the year to June 2025 was 670,000, while total emigration was 693,000 — meaning more people left than arrived in that 12‑month window, even though net migration remained positive after other adjustments.

The drop has been driven largely by falls in work and study migration, and by a sharp swing in study dependants, which have turned negative.

Composition of the latest ONS estimate

Breaking down the year to June 2025 ONS estimate:

• Non‑EU+ net migration: +383,000
• EU+ net migration: -70,000
• British net migration: -109,000
• Asylum net migration: 90,000, which is 44% of the total net migration estimate (compared with 22% before Brexit)

For local councils and schools, the mix matters as much as the headline total, because asylum seekers’ support needs differ from those arriving on work visas or student routes.

Policy responses and forecasting challenges

Mahmood’s Home Office has tightened parts of the system that were driving the post‑pandemic rise, including:

• Limits on dependants
• Higher pay thresholds for some work visas

Ministers argue these steps are needed to restore control and protect public services, and Labour has said it wants net migration to fall. Yet the OBR’s numbers suggest that even when arrivals slow, longer stays can keep net migration higher than politicians expect.

According to analysis by VisaVerge.com, the gap between arrivals and how long people remain has become one of the hardest aspects of UK migration forecasting. This gap depends on:

• Job market conditions
• Rent levels
• Family decisions
• Whether people see a future in Britain

Government paper and public debate

A UK government paper published in May 2025 also hinted at the tension between arrivals and stays, saying recent high levels may “settle in the region of 300,000 per year or more.” The document did not explicitly name an adviser predicting exactly 300,000, and its language aligns more with OBR and ONS assumptions that the long‑run level could be closer to the mid‑300,000s. UK government paper published in May 2025

This matters for public debate because a claim of “300,000 by the end of the decade” can sound like a cap or a target, while fiscal and statistical bodies point to 340,000 by 2030 as a central forecast.

Sensitivity of population models

Researchers at the Migration Observatory (University of Oxford) warn that small changes in assumed net migration can shift the long‑term population picture by millions. Migration Observatory (University of Oxford)

• Example: If net migration averaged 525,000 a year, the UK population would be 2.4 million higher by 2037 — roughly 3% more than under the ONS principal projection.

Their point is that no single number is certain; these models are sensitive, and policy choices on visas, enforcement, and settlement can ripple through the forecasts.

Practical consequences for employers and services

The mix of falling short‑term numbers and higher long‑term forecasts creates planning difficulties:

• A care provider seeing net migration of 204,000 in the year to June 2025 may worry about immediate staff gaps.
• Budget planners must consider the OBR path back up later in the decade.
• Universities can feel the drop in study arrivals and dependant changes quickly through fee income.

Human side of “stay rates”

The source material does not name individual migrants affected by these shifts, but the OBR’s “stay rate” story usually comes down to personal decisions:

• A graduate finding a sponsor
• A family choosing to live together
• Someone who fears they cannot return if they leave

Those choices explain why visa crackdowns can cut arrivals quickly while the longer‑run net migration line in forecasts still rises.

Key takeaway: Short‑term falls in net migration can coexist with higher long‑run projections because longer stays by migrants — driven by labour markets, family choices and settlement paths — push forecasts up.