Selling a rental property isn’t just about Estate-agent fees and completion dates — it’s about understanding Capital Gains Tax (CGT).
Many Landlords are surprised by how quickly CGT adds up when they sell or transfer a buy-to-let.
Here’s a clear breakdown of how the tax is calculated and what you can deduct.

📺 Watch: Selling a Buy-to-Let Property – CGT Explained (UK 2025)

When CGT Applies

You pay CGT when you Sell, Gift or Transfer a property that:

  • Is not your main home, or
  • Has been rented out at any point.

If you’re transferring a property to an ex-partner rather than selling it, the tax rules are different — see our guide on Transferring a Property After Separation: What Tax Applies When You’re Not Married

It’s the gain, not the sale price, that’s taxed — so your goal is to reduce that gain with every legitimate cost and relief available.

Step 1: Work Out the Gain

Example figuresAmount
Sale price (March 2025)£230,000
Less purchase price (July 2010)£150,000
Initial gain£80,000

Step 2: Deduct Allowable Costs

These reduce the taxable gain — not your income.
You can usually deduct:

  • Estate agent and Solicitor fees
  • Stamp Duty and legal costs from the original purchase
  • Capital improvements (e.g. extensions, new kitchen)
  • Professional fees directly related to sale or acquisition
Deductible costsAmount
Estate agent + Solicitor£4,000
Improvements (new kitchen, bathroom)£12,000
Stamp Duty on purchase£3,000
Total allowable costs£19,000

  Adjusted gain: £80,000 − £19,000 = £61,000

For a full list of what you can claim when selling, see our blog What Expenses Can You Claim When Selling a Rental Property? — it outlines which costs HMRC accepts and which are often disallowed.

Step 3: Apply Reliefs and Exemptions

  • Annual CGT exemption: £3,000 (2025/26)
  • Private Residence Relief (PRR): if you ever lived there as your home.
  • Lettings Relief: only available in limited cases where PRR also applies.

If you lived in the property for three out of fifteen years, PRR could exempt that portion of the gain.

Example:

£61,000 × (3 years / 15 years) = £12,200 exempt under PRR
Remaining taxable gain = £48,800 − £3,000 (annual exemption) = £45,800

Step 4: Apply the Correct CGT Rate

Residential property gains are taxed at:

  • 18% if you’re a basic-rate taxpayer, or
  • 24% if any part of the gain pushes you into higher-rate territory.

For a higher-rate taxpayer:

£45,800 × 24% = £10,992 CGT payable

Step 5: Report and Pay Within 60 Days

HMRC requires UK residential property disposals to be reported and paid within 60 days of completion.
Miss the deadline and you’ll face penalties and interest.

Step 6: Keep Every Record

Keep:

  • Completion statements
  • Purchase and Sale contracts
  • Invoices for improvements and professional fees

HMRC can ask for evidence up to six years after you file the return.

How to Reduce Future CGT

  • Time sales across different tax years to use multiple exemptions
  • Transfer part ownership to a Spouse before sale (if married)
  • Track all improvement costs as you go
  • Consider a Property Tax Review before committing to sell

Thinking of reinvesting the proceeds through a company? Our blog on Limited Company or Personal Name – Which Is Better for Rental Property in 2025 explains how the structure affects future tax and ownership.

Key Takeaways

  • CGT applies to the gain, not the sale price
  • Deduct allowable costs and improvements to reduce the gain
  • Use your annual exemption and PRR where available
  • Report within 60 days
  • Keep full records — HMRC can check later

Need Help Calculating CGT on Your Property Sale?

A Property Tax Review can show exactly what’s taxable, which costs qualify, and how to plan your sale for the lowest liability.
Email info@gracecertifiedaccountants.com or book a clarity call to get started.

A note from the author: