If you’re a UK 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 non-residents selling UK property.
Why Does Rebasing Exist for Non-Residents Selling UK 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.
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.
How Rebasing Works in Practice for UK Property Sales
👉 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.
Who Can Use Rebasing When Selling UK Property?
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 structures have different dates and rules, but for most non-resident landlords selling UK homes, 6 April 2015 is the key date.
Do Non-Residents Have to Use Rebasing?
No - and this is where things get interesting.
Non-residents can usually choose between three methods of calculating the gain:
1. Rebasing method
Uses the 6 April 2015 market value (most common)
2. Time-apportionment method
Calculates the gain over the entire ownership period and then taxes only the portion after April 2015.
3. 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
Professional advice is often essential here.
Why a 6 April 2015 Valuation Is So Important
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 pulled from an online property site may not stand up to scrutiny.
How Non-Residents Must Report a UK Property Sale
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, and penalties apply for late filing.
Why Rebasing Can Make a Huge Difference to Your Tax Bill
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 choice of valuation strategy
For many non-resident investors, rebasing is the single most important factor in calculating their UK property CGT correctly.
Key Takeaways for Non-Residents Selling UK Investment Property
Key Takeaways for Non-Residents Selling UK Investment Property
If you’re a non-resident selling a UK investment property, rebasing is not just a technical detail — 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 tax and from unwanted attention from HMRC.
If you’re planning a sale, getting advice before exchange of contracts is often the smartest move, so contact our specialist teams at:
01249 816 810
FAQs
What is rebasing for UK property Capital Gains Tax?
Rebasing is a method used to calculate 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 non-residents selling UK residential property, this date is 6 April 2015.
Why is 6 April 2015 important for non-resident landlords?
6 April 2015 is the date when the UK extended Capital Gains Tax to non-residents selling UK residential property. Gains arising before this date are generally excluded from UK tax under rebasing.
Can a non-resident choose not to use rebasing?
Yes. Non-residents 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?
While not legally mandatory, a professional retrospective valuation is strongly recommended. HMRC can challenge unsupported or unrealistic valuations, particularly where significant tax savings are involved.
Does rebasing apply to commercial UK property?
Commercial property follows different rules and dates. The 6 April 2015 rebasing date primarily applies to UK residential property owned by non-residents.
Do I still have to report the sale if no CGT is due?
Yes. Non-residents must report the sale of UK property to HMRC within 60 days of completion, even if no tax is payable.
Can rebasing reduce my Capital Gains Tax significantly?
Yes. Rebasing often removes many years of historic growth from the UK tax calculation, which can substantially reduce the taxable gain.
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