A UK exit tax is not law today. However, it emerged as a genuine policy risk after the government floated the idea in the run-up to the 2025 Budget. Although the proposal was ultimately dropped, it showed the Labour government’s apparent willingness to consider new ways of taxing the better off without raising headline income tax or VAT rates. Several voices in government and policy circles also called for an exit tax, noting that many comparable countries already operate similar systems.
For British expats in Thailand, and those preparing to move here, this matters. An exit tax would alter both the timing and the cost of leaving the UK tax system and could change how individuals manage their assets before and after becoming non-resident. Understanding how such a tax might work is sensible preparation. It helps you make informed decisions about residency and asset planning and reduces the risk of being caught by surprise if the idea returns in a future Budget.
This article explains what an exit tax is, how close the UK came to introducing one in 2025, why the concept may re-emerge, and what it could mean for British nationals already living in Thailand or planning a move.
What Is an Exit Tax?
An exit tax is a charge on unrealised capital gains that have built up during someone’s period of UK tax residence. It would apply to anyone leaving the UK and becoming non-resident, including British nationals who have lived in the UK their entire lives. Under such a system, an individual is treated as if they sold their assets on the day they depart, and the UK taxes the gains that accumulated during their time as a UK resident, even though no real sale has taken place.
In countries that operate exit tax systems, the rules usually apply to assets such as:
- Shares and fund units
- Business interests
- Investment portfolios
- In some cases, digital assets
UK property would not normally fall under an exit tax because non-residents already pay UK capital gains tax on gains from UK real estate.
The purpose of an exit tax is straightforward. It is designed to prevent people from building up gains while resident in a country, then leaving and selling their assets elsewhere without paying tax on wealth created during their period of residence. A lifelong British resident would likely be treated in the same way as someone who lived in the UK for only a few years; the focus is on where the economic gain arose, not nationality.
The 2025 UK Exit Tax Proposal: What Really Happened
Although no exit tax exists today, the UK came closer to introducing one in 2025 than many people realise.
In the weeks before the Autumn Statement, the Treasury examined a proposal for a 20% exit charge on unrealised gains built up during a person’s period of UK residence. This would have applied to anyone ceasing to be UK resident, not only non-doms or foreign nationals. The proposal was modelled on international systems already used in countries such as Canada and Australia.
This was widely reported across authoritative sources, including:
- Saffery, whose November 2025 briefing confirmed that the Treasury had explored the introduction of an exit tax and later abandoned the plan due to concerns about a sudden wave of departures
Reuters, which reported that the Treasury was reviewing a 20% charge on unrealised gains for - Bloomberg, which also covered the proposed exit charge and its potential impact on mobility
- The Times, which discussed the emerging exit-tax concept and concerns from entrepreneurs
- Think-tank modelling, including proposals for rebasing on arrival and deemed disposal on departure, a structure used in several OECD countries (See below).
The proposal was abandoned only days before the Autumn Statement due to concerns over capital flight. Officials feared a ‘rush for the door’ if taxpayers were given any notice.
The key point is that this was not abstract speculation. The proposal reached advanced evaluation inside the Treasury and was dropped at a late stage. That alone makes it a policy risk worth understanding.
Why the Risk Remains Under a Labour Government
The decision not to include the exit tax in the 2025 Budget does not mean the idea has disappeared. There are compelling reasons why it could return.
Fiscal Pressure on the UK Exchequer
The Office for Budget Responsibility’s November 2025 forecast shows lower projected nominal GDP growth and materially weaker corporate-profit forecasts than earlier projections:
At the same time the government maintained its pledge not to raise income tax, National Insurance or VAT.
This combination of constrained tax levers and significant spending pressure pushes attention towards capital-based measures. Advisory firms noted that revenue pressure was a major driver for considering an exit tax.
Political Logic
Exit taxes are politically easier to justify. They target those leaving the country rather than the wider population and therefore carry low political cost.
Policy Precedent
Ideas that reach formal Treasury modelling rarely vanish. The exit tax already went through design work, rate testing and legal review. Such proposals often return in future Budgets, especially during periods of fiscal stress.
For these reasons an exit tax remains a realistic policy risk during Labour’s term, even though nothing has been announced.
International Context and Precedent
Exit taxes are common in other OECD countries. The UK is unusual in not having a general exit tax for individuals.
Examples include:
- Canada: A deemed disposal is applied when someone becomes non-resident. Gains arising during Canadian residency are taxed.
- Australia: When leaving Australia certain assets are treated as sold at market value unless the taxpayer elects to keep them within the Australian tax net.
- France and Norway: Both apply exit taxes on latent gains in significant shareholdings, with deferral options.
- Netherlands: The Netherlands applies one of Europe’s oldest exit tax regimes. Individuals with a substantial shareholding (5% or more) may face tax on latent gains when leaving the Netherlands.
United States: The US applies an exit tax to ‘covered expatriates’ who renounce citizenship or long-term residency.
These systems are important because they illustrate the likely shape of any UK regime. The Treasury’s 2025 work clearly drew on these international models.
How a Future UK Exit Tax Might Work
If introduced, a UK exit tax would likely include the following features:
Trigger Date
The charge would arise when a person becomes non-UK resident. To avoid behavioural distortion, it would likely apply immediately or from Budget Day, making forward planning essential.
Assets Covered
Likely to include:
- Shares and fund units
- Interests in private companies
- Investment portfolios
- Digital assets
UK property is already taxed under non-resident capital gains tax.
Gains Included
Only gains that accrued while the individual was UK resident. A ‘rebasing on arrival’ system could exclude gains from before someone moved to the UK.
Payment Timing
A deferral mechanism is likely, given that the tax would apply to unrealised gains. Payment may be delayed until the asset is sold, but with:
- Security required
- Interest charged
- Ongoing reporting obligations
Interaction with Tax Treaties
The exit tax would apply before a person becomes resident elsewhere. The UK–Thailand treaty would not prevent the UK from taxing gains up to the departure date.
Exit Tax Implications for British Expats Living in Thailand
For those who have already left the UK a future exit tax is unlikely to apply retrospectively. Once non-residency is established the departure trigger has passed. Even so, several points remain important for protecting your position and limiting future UK exposure.
Keep clear evidence of when you ceased UK residence, including travel records, the date your UK ties ended and any supporting documentation. Establishing your non-residency is essential because the exit charge would only apply at the point of departure.
Asset valuations at your departure date may be useful if HMRC ever requests supporting information. Having contemporaneous valuations helps demonstrate what gains belonged to your UK period of residence and what accrued afterwards.
If you still hold significant UK-based investments or business interests consider whether retaining these assets in the UK is in your best interest.
While a future exit tax would not apply to past departures, UK-sited assets can still create ongoing exposure:
- They may maintain or strengthen your connection to the UK for tax-residency purposes
- They can trigger UK tax charges independently of any exit tax (e.g. Non-Resident CGT, UK dividend or interest withholding rules)
- They may become subject to new rules in the future if the UK introduces additional wealth-related measures
For these reasons many expats review, reduce or restructure UK-sited assets after leaving the country. This helps reinforce a clean non-residency position and reduces the risk of being drawn back into the UK tax net through future reforms.
Continue to plan carefully around remittances into Thailand
Under Thailand’s post-2024 rules, foreign income earned in a given year becomes taxable if it is brought into Thailand in the same year. Understanding how and when you transfer funds is therefore essential, even if UK rules do not change.
Exit Tax Implications for British Nationals Considering Thailand Move
People preparing to leave the UK are the group most exposed to a sudden policy change. It is therefore sensible to understand:
- your intended date of departure
- the level of embedded gains in your investments
- whether restructuring assets before departure would be beneficial
- how a UK exit tax would interact with Thailand’s remittance rules
- the sequencing of disposals, transfers and remittances
A well-timed and well-planned move can make a material difference to your long-term tax position.
How British Expats Can Prepare for a Possible UK Exit Tax
Being proactive does not mean expecting an exit tax. It simply means avoiding the risk of being caught off guard.
Useful steps include:
- understanding your UK tax residency position
- reviewing your investment portfolio for embedded gains
- considering changes before departure if appropriate
- documenting valuations for key assets
- understanding how Thailand taxes foreign income remitted after 2024
- seeking advice early if planning a move
These steps provide clarity and reduce the risk of unexpected outcomes.
Balanced Perspective: Should Expats Worry?
There is no exit tax today, and nothing has been announced. Even so, the idea has been examined in detail inside the Treasury and could reappear in a future Budget, particularly as the government seeks revenue without raising headline tax rates.
Awareness is sensible. Panic is not.
Good planning ensures you stay in control regardless of what the UK decides.
Planning to Reduce Exit Tax Risk
The UK has not introduced an exit tax, but the idea remains active within policy discussions. For British expats in Thailand, and those considering a move, it is wise to understand how such a tax could operate and how it might affect your planning.
Good planning reduces the risk of unwelcome surprises and supports clear decision-making.
How We Can Help
If you want clarity on how a future UK exit tax might affect you, or guidance on structuring a move to Thailand, our team is here to help. Book a free call and we will walk you through your position in plain English
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