The decision to move abroad is often dominated by logistics: sorting accommodation, managing the job transition, shipping household goods. Tax planning — which is arguably more consequential financially — is frequently left to the last minute or overlooked entirely.
The tax year immediately before you leave the UK is one of the most valuable for financial planning. Once you are non-resident, some of these opportunities close; others open up. The time to act is before departure.
Here are the key areas to consider. This is a framework, not a prescription — the right approach for your circumstances depends on individual factors, and professional advice is essential.
1. Crystallise capital gains before becoming non-resident
When you are a UK tax resident, you pay UK capital gains tax (CGT) on gains from the disposal of most UK and overseas assets. When you become non-resident, the position changes significantly.
Overseas assets: Once you are non-UK resident, you are generally not subject to UK CGT on gains arising on overseas assets (shares, funds, foreign property). This means that if you have significant unrealised gains on non-UK investments, leaving the UK starts the clock — from the point of non-residence, future gains on those assets will typically be outside the UK CGT net.
However, if you subsequently return to the UK within a five-year period (under the temporary non-residence rules), gains accrued during your non-residence period can be treated as arising in the year of return and taxed then. This is a common trap for people on shorter overseas assignments.
UK assets: UK residential property remains within the UK CGT regime regardless of your residence status. CGT on UK commercial property and UK-listed shares is more complex — consult an adviser.
Action: Review your portfolio before leaving. If you have assets with embedded gains that you intend to retain long-term (and which may be outside the UK CGT net once you leave), there is no urgent reason to crystallise. If you have assets with gains that you intend to sell relatively soon, consider timing the disposal relative to your departure.
2. Make pension contributions while still a UK taxpayer
Pension contributions attract tax relief at your marginal UK rate. A higher-rate taxpayer contributing to a pension receives 40% (or more) relief — which is one of the best guaranteed returns available anywhere in personal finance.
Once you become non-resident, your ability to make UK pension contributions and receive tax relief is severely curtailed. You can typically contribute up to £3,600 gross per year and still receive basic-rate relief for up to five years after leaving — but the opportunity for higher-rate relief disappears immediately on departure.
Action: If you are a higher or additional rate taxpayer, maximise pension contributions in the tax year you leave — and consider whether you have unused carry-forward allowances from the previous three tax years that you can use. The annual allowance is £60,000 (as of 2026); carry-forward can allow contributions significantly above this in a single year.
This is particularly relevant if you have received a large bonus or other one-off income in your final UK tax year.
3. Review assets held between spouses
Transfers of assets between spouses or civil partners are normally free of CGT (at no gain/no loss). This allows couples to use both partners' annual CGT exemptions and basic-rate tax bands.
If one spouse is moving abroad and the other is not (or if the timing of departure differs), the window for tax-efficient transfers between spouses as UK residents may be closing. Gifting appreciated assets to the lower-rate taxpayer before departure can be worthwhile.
Action: Review the ownership of investments and assets in the context of both spouses' tax positions — now and after the move.
4. Review wills and cross-border succession
Your existing UK will may not be valid or effective in your new country of residence. This is particularly important if the new country has forced heirship rules — legal requirements about how your estate must be distributed that can override the terms of your will.
Within the EU, the Brussels IV regulation allows EU-resident individuals to elect for their will to be governed by the law of their nationality rather than their country of residence. This is worth making explicitly if you are moving to an EU country with forced heirship provisions.
Action: Arrange for your will to be reviewed (and if necessary redrafted) before you leave. Consider whether you need a will in both the UK and your new country. If you own UK property, a UK will remains essential.
5. IHT exposure: domicile and the long-term residence rules
UK inheritance tax is no longer determined by domicile alone. Since April 2025, the IHT regime has two separate triggers:
Domicile: UK-domiciled individuals (wherever resident) remain subject to UK IHT on their worldwide estate. Acquiring a domicile of choice abroad requires genuine, demonstrable intention to settle permanently and takes time to establish.
Long-term UK residence (from April 2025): Independently of domicile, individuals who have been UK resident for 10 or more of the last 20 tax years are treated as "long-term UK residents" for IHT and remain subject to worldwide IHT. Crucially, this IHT exposure persists for up to 10 years after departure — an individual with 15 years of UK residence who leaves today remains within the UK IHT net for a further 10 years, even if they have never been UK-domiciled.
This means that non-doms who were previously outside UK IHT on non-UK assets may now be within it, and that simply leaving the UK does not immediately end worldwide IHT exposure for long-term residents.
If you make lifetime gifts before leaving (starting the seven-year PET clock), those gifts will potentially be outside your estate within seven years — but only once the IHT tail has also expired.
Action: If you have not yet started making regular gifts within the various IHT exemptions (annual exemption, normal expenditure out of income), starting before you leave is sensible. The clock runs regardless of where you subsequently live. Obtain specialist advice on whether the long-term residence rules apply to your situation and how long your IHT tail will last post-departure.
6. ISAs: what happens to them
UK ISAs continue to shelter existing investments from UK tax after you leave — your existing ISA balance retains its wrapper. However, you cannot make new ISA contributions as a non-resident. The ISA wrapper is for UK residents.
Action: Consider maximising ISA contributions in the tax year you leave (£20,000 per individual as of 2026, or £4,000 for a Lifetime ISA). Once you are non-resident, that contribution capacity is lost.
Note that although income and gains within an ISA remain free of UK tax, you will need to check whether your new country of residence treats the ISA as transparent for local tax purposes. Some countries do not recognise the UK ISA wrapper.
7. Timing of income: salary and bonus
The timing of salary, bonus, and other earned income relative to your departure date can make a material difference to your UK tax position. If you can structure the receipt of a large bonus to fall after you become non-resident — and your new country does not tax it, or taxes it less — the tax saving can be substantial.
This requires coordination between your employer, your UK tax adviser, and sometimes the tax authority of your destination country. The Statutory Residence Test (SRT) provides specific rules about which income belongs to the UK period and which to the overseas period in a split year.
Action: Discuss with your employer and a UK tax adviser whether there is flexibility in the timing of variable compensation, particularly in the year of departure.
Start planning early
The common thread across all of these actions is time. Most of them require several months to implement properly. Pension contributions need to be processed; asset transfers need legal steps; wills need drafting and execution; gifts are most effective when started early. Leaving tax planning to the week before departure is too late.
The rules described in this article are based on UK tax law as of June 2026 and are subject to change. Tax planning for internationally mobile individuals is complex and individual — this article is a framework, not a prescription. Contact us to arrange a pre-departure financial review.
This article is for general information only and does not constitute financial, legal or tax advice. Rules, prices and regulations change; verify current requirements with a qualified adviser before acting.