Foreign Income

How do I claim double taxation relief in the UK?

Answered by Jordan Onraet-Wells, Founder & Chartered Tax Adviser (CTA). Published 9 August 2026. Last reviewed 9 August 2026.

The short answer

If you are UK resident with foreign tax to relieve, you claim Foreign Tax Credit Relief through Self Assessment on the SA106 foreign pages, filed with your SA100 return. The credit is the lower of the foreign tax paid and the UK tax due on that same income, calculated separately for each source, and it can never exceed the UK tax on the item. If instead you live in a treaty country and want relief on UK-source pensions, annuities, interest or royalties, the form is DT-Individual, not the SA106.

UK residents claim Foreign Tax Credit Relief on the SA106 foreign pages with the SA100 return; helpsheet HS263 sets out the per-source calculation.
The credit is the lower of the foreign tax paid and the UK tax on that same income; foreign tax above the cap is not repayable by HMRC and can only be recovered from the foreign authority.
A separate calculation is required for each source of income or gain: surplus credit from one source cannot soak up UK tax on another.
Relief comes by treaty where one covers the income, or as unilateral relief under TIOPA 2010 where none does; unilateral relief is capped to the treaty-equivalent amount.
Form DT-Individual is only for residents of a treaty country claiming relief on UK-source pensions, purchased annuities, interest and royalties.

Fixed-fee service

Overseas income on your UK tax return

Standard £450. Non-Resident and Expat £750. Complex from £950.

A Chartered Tax Adviser prepares the SA106 foreign pages, claims Foreign Tax Credit Relief source by source and files the return as your authorised agent. Returns with several foreign sources, investments or gains fall under the Complex Personal Tax Return, from £950. We tell you which published fee applies after a short call, and your fixed quote is agreed in writing before work starts. That is the total. Never hourly.

SA106 foreign pages: overseas interest, dividends, foreign pensions, pooled overseas rental profit and your Foreign Tax Credit Relief claim
SA109 residence and FIG pages where a FIG claim, split-year treatment or Overseas Workday Relief applies
Every foreign amount converted into sterling at the rate when it arose, whether or not it reached the UK
Any FIG claim modelled against the allowances it costs, then the whole return filed as your authorised agent

Overseas income returns

Which form you use depends on which side you are on

There are two claim routes, and mixing them up wastes months. A UK resident relieving foreign tax on worldwide income claims through Self Assessment on the SA106 foreign pages: you report the foreign income, the foreign tax suffered and your Foreign Tax Credit Relief claim, all filed with the SA100. Form DT-Individual does the opposite job: it is for a resident of a treaty country claiming relief from UK Income Tax on UK-source pensions, purchased annuities, interest and royalties, both at source and as a repayment of tax already deducted. It is not a general foreign-relief form, so do not reach for it if you live in the UK.

How the credit is calculated, and why it is capped

Foreign Tax Credit Relief is the lower of two figures: the foreign tax actually paid or allowed under the treaty, and the UK tax due on that same income. That second figure is a hard cap, worked out separately for each source. If the foreign rate is higher than your UK rate on the item, the excess foreign tax cannot reduce your UK bill and HMRC will not repay it; your only route is to recover it from the foreign authority, often by claiming the treaty rate there. You can instead elect to deduct the foreign tax from the foreign income rather than take a credit, but that only helps in narrow cases such as where the UK tax on the item is nil or you have losses. Our guides to foreign rental income and foreign pensions show the calculation for the two most common sources.

Treaty relief, unilateral relief and the tie-breaker

Treaty relief is the first port of call: the UK has more than 100 agreements that allocate taxing rights and can reduce foreign withholding at source. Where no treaty covers the income, unilateral relief under TIOPA 2010 fills the gap, but it is capped to the treaty-equivalent amount, so the route rarely changes the figure. If both countries treat you as resident, the treaty tie-breaker decides in a fixed order: permanent home, centre of vital interests, habitual abode, nationality, then mutual agreement, stopping at the first test that resolves it. Horizon runs the whole claim, the per-source SA106 figures and the credit-versus-deduction test on fixed fees agreed upfront; book a free clarity call at /book and we will tell you what your relief is worth before you commit.

Go deeper

Sources and further reading

This is general information for the 2026/27 UK tax year, not personal tax advice; speak to a Chartered Tax Adviser about your own position.

Deadline 31 January 2027

Filing a 2025/26 return?

A Chartered Tax Adviser prepares and files it for you, including the pages HMRC's free online service cannot handle. Fixed fees from £450, non-resident and expat returns £750 fixed, agreed before any work starts.

Overseas Income on Your UK Return

Applies to you? Ask us directly

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