Tax Planning Before Leaving the UK: What to Do in the Final Years of UK Residency

Leaving the UK — whether to retire abroad, take up an international role, or establish a more tax-efficient base — is a major life transition with significant financial implications. The years immediately before departure are a window in which the full complement of UK tax reliefs is available: the annual CGT exempt amount, pension contributions at UK marginal rates, Gift Aid, ISA contributions, and others. This window closes when you become non-UK resident.

Planning should begin at least three years before intended departure — ideally earlier. Here is a structured approach to the most important actions.

Realising Capital Gains While UK Resident

Non-UK residents are generally subject to UK CGT only on UK land and property (and property-rich companies). Gains on UK shares, funds, and non-UK assets are typically not subject to UK CGT once you are non-resident. This creates a rational strategy: crystallise gains on non-property assets before you leave, using the UK's CGT regime which may (depending on your circumstances) be more favourable than the CGT regime of your destination country.

Equally, if you have assets sitting at a loss, you may wish to crystallise those losses before departure to generate allowable losses that can be carried forward and offset against future UK CGT (primarily from UK property disposals).

Annual exempt amount: The CGT annual exempt amount was £12,300 as recently as 2022–23, and has been reduced to £3,000 in 2026. While this limits the free crystallisation available each year, making use of the full £3,000 in each pre-departure tax year remains worthwhile.

Spousal transfers and exempt amounts: Transfers between spouses are not chargeable disposals for CGT. Transferring assets to a lower-rate taxpaying spouse before departure can reduce the total CGT on a full crystallisation — though the donee spouse takes on the original base cost.

Asset location review: Consider whether any assets currently held outside tax wrappers could be transferred into ISAs before departure (the ISA annual allowance cannot be used after becoming non-resident). Any assets you expect to sell in the next five years post-departure should be reviewed for pre-departure crystallisation.

Maximising Pension Contributions at UK Rates

Pension contributions receive income tax relief at the contributor's marginal rate — 40% for higher-rate, 45% for additional-rate taxpayers. This relief is available during UK residency and not available once non-resident.

Annual Allowance: The pension Annual Allowance is £60,000 gross per year in 2026 (tapered for high earners above the adjusted income threshold of £260,000). Contributions that exceed unused annual allowance incur a charge equal to the marginal rate of tax.

Carry Forward: Unused Annual Allowance from the three prior tax years can be "carried forward" and used in the current year, potentially allowing very large one-off contributions. For example, if you made no contributions in 2022–23, 2023–24, and 2024–25, you may be able to contribute up to £240,000 gross in 2025–26 (subject to having sufficient "relevant UK earnings" to support the contribution).

Before departure, assess:

• How many years of carry forward remain?
• What is the maximum contribution you can make in each pre-departure tax year?
• What is the optimal phasing of contributions to maximise relief while remaining within HMRC limits?

A large pre-departure pension contribution at 45% relief is one of the most financially impactful single actions available. A gross contribution of £100,000 costs a 45% taxpayer only £55,000 net; the pension grows gross thereafter.

IHT Implications of Departure: The Ten-Year Tail

UK IHT applies not only based on domicile but, following reforms effective from April 2025, also based on "long-term UK residence." Under the post-2025 framework, individuals who have been UK resident for 10 or more of the last 20 tax years become "long-term UK residents" for IHT purposes, and their worldwide assets remain within the scope of UK IHT.

Crucially, this IHT tail persists after departure until the individual has been non-UK resident for enough years that the 10-of-20-years test is no longer met — which can be up to 10 years post-departure for those with a long period of UK residence. An individual who leaves the UK after 15 years of residence will remain subject to UK IHT on worldwide assets for some years post-departure; the precise exit point depends on the number of UK-resident tax years still within the rolling 20-year window.

This has significant implications:

• Gifts made in the first years after departure — even to non-UK persons of non-UK assets — may still be PETs or immediately chargeable transfers within the UK IHT framework.
• Offshore trust planning implemented immediately post-departure may not achieve the intended IHT exclusion if the settlor remains a long-term UK resident for IHT purposes.
• The timing of major estate planning steps should be coordinated with when the IHT tail finally expires.

Specialist advice on the interaction between the Statutory Residence Test (income tax), domicile, and the new long-term residence rules (IHT) is essential for anyone planning a departure after a significant period of UK residence.

Making Charitable Gifts Before Leaving

Gift Aid, which allows charities to reclaim basic-rate tax and higher/additional-rate taxpayers to reclaim the difference via Self Assessment, is only available to UK taxpayers.

If you have significant charitable intentions — whether to specific organisations or more broadly — the years before departure, when you are a 40% or 45% taxpayer, are the most tax-efficient time to make those gifts. A £10,000 net donation by a 45% taxpayer before departure costs effectively £5,563 (after Gift Aid top-up and higher-rate reclaim). The same donation post-departure, as a non-UK taxpayer, receives no UK tax relief.

Consider:

• Front-loading charitable donations into the pre-departure years.
• Establishing a Donor Advised Fund (CAF charity account) while UK resident, funded with a large tax-efficient lump-sum contribution, then granting to specific charities over subsequent years from the fund.
• Donating appreciated shares before departure — no CGT on the donation, plus full income tax relief on the market value, both accessible only while UK resident.

Clearing HMRC Obligations

Before departure, ensure all UK tax affairs are fully in order:

Outstanding returns: Ensure all Self Assessment returns for prior years are filed and that any outstanding tax (or overpayments awaiting refund) is resolved. Unresolved HMRC matters become significantly more complex once you are overseas.

PAYE settlement: If you receive bonuses, share schemes, or other employment income subject to PAYE that may not have been correctly taxed, seek resolution before departure. HMRC has an Employee Compliance programme that can pursue unpaid PAYE for many years.

ISA contributions for the final year: Make maximum ISA contributions (£20,000 per year per individual) in the tax year of departure, before the date you become non-resident. You cannot contribute to a UK ISA as a non-resident, but ISAs already established can continue to hold investments tax-free after departure (no contributions, no forced closure). The ISA becomes a "frozen" tax-efficient wrapper.

VAT deregistration: If you are VAT-registered for a UK business and are ceasing UK-based trading, deregister from VAT before or at departure. File outstanding VAT returns and ensure any VAT on pre-paid contracts is correctly treated.

Notify relevant parties: Banks, investment platforms, pension providers, and HMRC should all be notified of your new address and non-resident status. P85 form notifies HMRC of departure. NSatI (National Savings) and Premium Bonds can generally be retained by non-residents.

The Statutory Residence Test: Getting It Right

The date on which you become non-UK resident — which determines when UK tax reliefs cease and overseas tax obligations begin — is determined by the Statutory Residence Test (SRT). This is fact-dependent and sometimes contentious.

Common errors include:

• Assuming you become non-resident from the day you leave (you do not — the SRT applies annual tests).
• Failing to count "ties" correctly (accommodation tie, family tie, work tie, 90-day tie, country tie).
• Assuming split-year treatment applies automatically (it must be claimed).

An incorrect assessment of your residence position can result in unexpected UK tax liabilities or a longer than anticipated UK exposure. Getting independent SRT analysis in the year of departure is strongly advisable.

How Global Investments Can Help

Pre-departure tax planning is one of the most time-sensitive and high-value services in financial planning — the window of opportunity exists only while UK residency continues, and some actions cannot be unwound after the fact.

Global Investments works with clients in the years leading up to a planned UK departure to design and execute a comprehensive pre-departure financial strategy — covering CGT crystallisation, pension maximisation, IHT planning (including the ten-year tail), charitable giving, and the resolution of all UK tax affairs.

We coordinate with specialist UK tax advisers and destination-country advisers to ensure a joined-up plan that captures all available reliefs and avoids costly errors.

UK tax rules are subject to change, including significant reforms to IHT residence rules effective from April 2025. This article provides a general overview as at 2026. This article is for informational purposes and does not constitute personalised tax advice. Always seek qualified professional advice for your specific circumstances.