In short: when a UK-resident individual sells a buy-to-let, Capital Gains Tax (CGT) is normally worked out on the gain, not the sale price. For a straightforward residential disposal in 2026/27, this page’s estimator uses the £3,000 annual exempt amount and 18%/24% residential-property CGT rates. It is deliberately narrow: if a relief, loss, former home, company, trust or another complication is involved, it stops and points you to the next step rather than guessing.
Tax year covered: 6 April 2026 to 5 April 2027. This is general information, not personal tax, legal or financial advice. Tax outcomes depend on the facts and the law at the time of disposal.
Simple 2026/27 buy-to-let CGT estimator
This planning tool is for one UK-resident individual selling their stable share of one directly owned, whole-interest UK residential buy-to-let. It uses whole-property figures, then applies your ownership share. It is not an HMRC calculator and cannot decide your filing obligation, reliefs or allowable costs.
This estimator needs JavaScript. Please use HMRC’s property CGT calculator where suitable and seek professional advice for a non-routine disposal.
When CGT can arise on a buy-to-let sale
Selling, giving away or otherwise disposing of a property can create a CGT calculation. For a straightforward sale, the starting point is usually the difference between what you receive and what the property cost you, after eligible costs. It is not a tax on the whole sale price. HMRC’s overview is Work out your gain when you sell property.
At its simplest, the calculation is:
sale proceeds − disposal costs − acquisition price − acquisition costs − qualifying enhancement/title costs = gain
Your annual exempt amount and any allowable losses are then considered under the wider CGT rules. The tax rate on a residential-property gain depends in part on how much of the basic-rate income-tax band remains after your taxable income. That is why two landlords with the same property gain can have different CGT results.
Which property costs may reduce a gain?
Broadly, the legislation allows acquisition costs, costs of disposal, and certain capital expenditure that enhances the asset and is reflected in it when sold. It can also cover expenditure on establishing, preserving or defending title. The statutory wording is in section 38 TCGA 1992.
Often worth checking
- Purchase price and SDLT.
- Solicitor/conveyancer, surveyor, valuer and agent costs that relate wholly to buying or selling.
- Estate-agent and legal fees on sale.
- Capital improvements, such as an extension, where the expenditure meets the legal test and remains reflected in the property at disposal.
- Qualifying title or boundary expenditure.
Do not assume these are deductible
- Mortgage interest or loan capital.
- Day-to-day repairs, redecoration, maintenance and running costs.
- Work that was only a repair rather than an enhancement.
- Costs already relieved elsewhere, or costs without an adequate record.
The distinction can be fact-specific. Keep invoices and get advice before treating a substantial project as enhancement expenditure.
Keep a disposal file
Keep the completion statements, contract and transfer documents, purchase and sale invoices, SDLT evidence, improvement invoices, planning/building paperwork where relevant, ownership records and your workings. HMRC says that a report needs the purchase and sale details, dates, relevant costs/reliefs and the calculation for each gain or loss.
2026/27 allowance and residential-property rates
For the 2026/27 tax year, this guide uses a £3,000 annual exempt amount. For residential-property gains made from 6 April 2026, the guide uses 18% for the part of the taxable gain within the unused basic-rate band and 24% for the remainder. The basic-rate income-tax band is £37,700. HMRC’s CGT rates page gives the worked method and 2026/27 examples; its Income Tax rates page confirms the tax-year bands.
In the estimator, the available basic-rate band is: £37,700 minus your taxable income before the gain, but never below zero. It applies the £3,000 annual exempt amount to this one gain and then divides the remaining gain between 18% and 24%.
Joint owners, former homes and cases this tool does not estimate
Joint owners
Joint owners generally work out the gain for the share they own. That does not mean there is one joint annual exempt amount: each person’s CGT position, annual exempt amount, losses, income and reliefs need considering separately. The estimator can only apply one fixed, known share to otherwise straightforward whole-property figures.
A property that was ever your home
Do not assume that a former home is simply a buy-to-let sale. Private Residence Relief can depend on periods of occupation and other facts. Lettings Relief is also restricted and does not apply just because a former home was let. Start with HMRC’s guidance on tax when selling your home and letting out part of your home, then obtain advice where needed. The estimator intentionally gives no figure for these cases.
Stop and use tailored guidance/advice if any apply
- You are non-UK resident, a company, partnership, trustee, personal representative or acting for an estate.
- You lived in the property, used it as a home, let only part of it, claimed/need a relief, or have business, commercial, land or mixed use.
- You acquired or are selling it by gift, inheritance, divorce/separation settlement, spouse/civil-partner transfer, connected-person transaction or undervalue.
- You are selling only a share/part, have changed ownership shares, have an option, conditional contract, deferred consideration or another non-standard disposal.
- You have other gains, disposals or capital losses, or your income position is more complex than the estimator’s stated assumptions.
- The property is or was a furnished holiday letting (FHL), or you think former FHL treatment affects the disposal. The separate FHL tax regime was abolished from 6 April 2025; do not carry forward old assumptions without checking the official abolition policy paper and getting advice.
For capital losses, see HMRC’s guidance on capital losses. For companies, CGT is not the same calculation as an individual’s direct disposal: take corporation-tax advice instead of adapting this page.
Report and pay: a practical sequence
- Before exchange: assemble the costs and ownership evidence; check whether a relief, market-value rule or other special rule applies.
- At exchange: note the contract date and the tax year. A normal unconditional contract is usually the CGT disposal date.
- At completion: check the 60-day UK-property reporting/payment position immediately if CGT is due. Do not wait for your accountant or your annual return to remind you.
- Afterwards: retain the calculation and documents. A Self Assessment return may still be needed, and the 60-day payment is an estimate/payment on account rather than a guarantee of the final year-end liability.
Use HMRC’s Report and pay your Capital Gains Tax hub and its specific UK residential property instructions for the current process. Deadlines and routes can change, so the official pages take priority over this guide.
Illustrative calculations - not tax advice
These examples show the arithmetic in the narrow estimator only. They assume every scope confirmation is true, a 2026/27 disposal and no losses, other gains or reliefs.
| Sale proceeds | £350,000 |
|---|---|
| Less purchase price, purchase costs, qualifying enhancement/title costs and sale costs | £228,000 |
| Gain | £122,000 |
| Less annual exempt amount | £3,000 |
| Taxable gain | £119,000 |
| £17,700 at 18% + £101,300 at 24% | £27,498 estimated CGT |
Here, £37,700 − £20,000 leaves £17,700 of basic-rate band. HMRC provides comparable rate examples on its CGT rates page.
Official sources and further Landlord Knowledge reading
Primary sources checked for this 2026/27 draft
- GOV.UK - Work out your gain when you sell property (gain, joint ownership, costs and special cases).
- GOV.UK - Capital Gains Tax rates (2026/27 annual exempt amount, residential rates and method).
- GOV.UK - Income Tax rates and Personal Allowances (2026/27 basic-rate band).
- GOV.UK - Report and pay CGT on UK property (current UK-property process and deadline).
- TCGA 1992, section 28 (time of disposal and acquisition) and section 38 (allowable expenditure).
Continue your landlord tax planning
Frequently asked questions
Is CGT charged on the full buy-to-let sale price?
Usually no. The starting point is the gain after the relevant acquisition, disposal and qualifying capital costs. The exact treatment depends on the facts.
Can I deduct a new kitchen or repairs?
It depends on what work was done and whether it meets the CGT enhancement rule. Routine repairs and maintenance are not automatically deductible from a capital gain. Keep evidence and take advice for material works.
What if the buy-to-let used to be my home?
Do not use this estimator. Private Residence Relief and possibly the restricted Lettings Relief rules may matter; check the official home-sale guidance and obtain advice.
Does the 60-day payment settle all my tax?
Not necessarily. It is generally a property CGT report/payment on account. Your final position can change with the rest of your tax-year income, gains, losses and return position.
