Owning a property abroad is not, by itself, something you declare. Income from it and gains on it are - and if you are UK resident, that applies whether or not the money ever comes to the UK.
Two questions get muddled here, and separating them removes most of the confusion. Owning an overseas property is not, by itself, something you declare on a UK tax return. There is no box for “I have a flat in Thailand”. What you declare is income from it and gains on it.
If you are UK resident for tax purposes, you are taxed on your worldwide income, not just your UK income. So if the property is let — whether through a hotel-managed rental programme, a local agent or directly — that rental profit is UK-taxable income and goes on your Self Assessment return, on the foreign pages (SA106). It does not matter that the money never reached a UK bank account, and it does not matter that Thai tax was already paid on it.
You will also need to declare when you sell, if there is a gain — covered separately in UK capital gains tax on selling an overseas property.
This catches people out. HMRC treats your overseas property letting as a different business from any UK property letting you do. The practical consequence is that losses do not cross over: a loss on your Thai apartment cannot be set against profit from a buy-to-let in Manchester. Losses on the overseas business are carried forward against future profits of that same overseas business.
You are taxed on the profit, not the gross rent, so allowable expenses come off first — management and letting commission, the service charge, insurance, repairs, and other costs incurred wholly and exclusively for the letting. Capital items are treated differently from repairs, and finance costs for residential property are restricted rather than fully deductible. Everything must be converted into sterling.
There is also a small property allowance that can remove the reporting obligation entirely if your total property income is below it — check the current threshold on the HMRC page linked below before assuming you are under it.
Thailand will generally tax rental income arising from a Thai property, and the UK will tax the same profit in your hands as a UK resident. Foreign Tax Credit Relief is what stops that being a double charge: broadly, you claim credit for the Thai tax paid against your UK liability on the same income, capped at the UK tax due on it. It equalises upwards to the higher of the two rates rather than letting you pay the lower — see the UK–Thailand double taxation agreement.
A note on figures. Rates, allowances and thresholds change at every Budget, and this page is written as at July 2026. We have deliberately kept specific numbers off it and linked to HMRC instead, so that you are reading the current figure rather than one we published months ago. The mechanics below are stable; the numbers are not. This is general information and not tax advice — take advice on your own circumstances before you act.
Primary sources
Thinking about a property abroad and want the tax picture straight first?
See if you qualify →There is no requirement to declare mere ownership of an overseas property on a UK tax return. What is declarable is income from it and any gain when you sell. If it sits empty and earns nothing, there is generally nothing to report until you dispose of it.
On the foreign pages, SA106, of your Self Assessment return. It is reported as profit after allowable expenses, converted into sterling, and it must be declared even if the income never leaves the country it arose in.
No. HMRC treats an overseas property business as separate from a UK property business, so losses are ring-fenced. An overseas loss is carried forward against future profits of that same overseas business.
You still report it in the UK, but Foreign Tax Credit Relief lets you set the Thai tax paid against the UK liability on the same income, capped at the UK tax due. In effect you pay the higher of the two rates overall rather than both in full.
Reviewed 2026-07-20 · Written by James Allwinton, who runs the research and the numbers behind every introduction at The Expat Investor. We are an introducer, not a financial, legal or tax adviser — this is general information, not advice.
How we source this: UK tax mechanics follow HMRC's published guidance on GOV.UK, linked inline on each page, and the UK–Thailand double taxation convention. Rates and thresholds change at each Budget, so we link to the live HMRC page rather than reprinting figures that go stale. This is general information, not tax advice — your own position depends on your residence, your other income and your holding structure. Figures for any specific building — price, service charge, sinking fund and the net yield actually achieved — are confirmed with you privately rather than published here.