If you’re a UK expat or non-resident thinking about selling a UK investment property, you may have come across the term rebasing and wondered what it actually means for your tax bill. Rebasing can significantly affect how much Capital Gains Tax (CGT) you pay, so it’s worth understanding clearly before you sell.
This article explains rebasing in plain English, why it exists, and how it applies to UK expats and other non-residents selling UK property.
Why Does Rebasing Exist for UK Expats Selling Property?
Before April 2015, most non-UK residents did not pay UK Capital Gains Tax on the sale of UK residential property. That changed when the UK government extended CGT to non-residents, including UK nationals living overseas.
To ensure fairness, the government decided that non-residents should not be taxed on gains that arose before the law changed. Rebasing was introduced to draw a line in the sand.
In simple terms, rebasing resets the property’s value for tax purposes to its market value at a specific date, rather than using the original purchase price.
What Is a Double Taxation Treaty?
If you are a non-resident selling a UK residential investment property, the default rule is this:
👉 Only the increase in value from 6 April 2015 to the sale date is subject to UK CGT.
Instead of calculating your gain from what you originally paid, the gain is calculated from the property’s market value on 6 April 2015.
Example
You bought a UK flat in 2008 for £200,000
Its market value on 6 April 2015 was £350,000
You sell it in 2026 for £500,000
Under rebasing:
Taxable gain = £500,000 − £350,000 = £150,000
The £150,000 increase before April 2015 is ignored for UK tax purposes
Without rebasing, the taxable gain would have been £300,000 – double the amount.
Which UK Expats Can Use Rebasing?
Rebasing generally applies if:
You are non-UK resident at the time of sale
The property is UK residential property
You owned the property before 6 April 2015
Commercial property and certain ownership structures have different dates and rules, but for most UK expats selling residential UK property, 6 April 2015 is the key date.
Do UK Expats Have to Use Rebasing?
No – and this is where planning becomes important.
Non-residents can usually choose between three methods of calculating the gain:
Rebasing method
Uses the 6 April 2015 market value (most common).
Time-apportionment method
Calculates the gain over the entire ownership period and then taxes only the portion after April 2015.
Original cost method
Uses the original purchase price (rarely beneficial, but sometimes useful if the property fell in value before 2015).
The best option depends on:
Property values at different dates
Length of ownership
Availability of a reliable 2015 valuation
For expats, this choice is often affected by where you live now, other overseas tax obligations, and double tax treaty interactions, so professional advice is usually essential.
Why a 6 April 2015 Valuation Is So Important for Expats
If you use rebasing, you must have evidence of the property’s market value at 6 April 2015. This usually means:
A professional retrospective valuation, or
Strong comparable sales data from that time
HM Revenue & Customs can challenge valuations they believe are unrealistic, so accuracy matters. An unsupported estimate from an online property portal may not stand up to scrutiny.
How UK Expats Must Report the Sale of UK Property
Non-residents selling UK property must:
Report the disposal to HMRC within 60 days of completion
Pay any CGT due within the same timeframe
This applies even if no tax is ultimately payable. Penalties apply for late filing, and these deadlines are often missed by expats unfamiliar with the UK reporting rules.
Why Rebasing Can Make a Huge Difference for UK Expats
Rebasing can:
Dramatically reduce the taxable gain
Prevent you being taxed on historic growth you were never meant to pay UK tax on
Influence the timing of a sale and the valuation strategy used
For many UK expats, rebasing is the single most important factor in calculating UK property CGT correctly.
Key Takeaways for UK Expats Selling UK Investment Property
If you’re a UK expat or non-resident selling a UK investment property, rebasing is not a minor technicality. It can mean tens or even hundreds of thousands of pounds difference in taxable gains.
Understanding how rebasing works, choosing the right calculation method, and supporting your figures with proper evidence can protect you from overpaying UK tax and from unwanted HMRC enquiries.
If you’re planning a sale, getting advice before exchange of contracts is often the smartest move.
📧 info@expat-tax-advice.co.uk
🌐 www.expat-tax-advice.co.uk
☎️ +44 1249 816810
FAQs (Frequently Asked Questions) Frequently Asked Questions: Rebasing and UK Property CGT for Expats
What is rebasing for UK property Capital Gains Tax?
Rebasing is a method of calculating Capital Gains Tax where the property’s value is reset to its market value at a specific date rather than using the original purchase price. For most UK expats and non-residents selling UK residential property, this date is 6 April 2015.
Why is 6 April 2015 important for UK expats?
This is when the UK extended Capital Gains Tax to non-residents. Gains arising before this date are generally excluded from UK tax under rebasing.
Can a UK expat choose not to use rebasing?
Yes. Expats can usually choose between rebasing, time-apportionment, or original cost. The most tax-efficient option depends on property values, ownership period, and valuation evidence.
Do I need a professional valuation for rebasing?
It is strongly recommended. HMRC can challenge unsupported or unrealistic valuations, particularly where large tax savings arise.
Does rebasing apply to commercial UK property?
Commercial property follows different rules and dates. The 6 April 2015 rebasing date mainly applies to UK residential property.
Do UK expats still need to report the sale if no CGT is due?
Yes. The sale must still be reported to HMRC within 60 days of completion, even if no tax is payable.
Can rebasing significantly reduce my UK Capital Gains Tax?
Yes. Rebasing often removes many years of historic growth from the UK tax calculation, substantially reducing the taxable gain.
Share this post: