Rates, the GBP 3,000 annual exempt amount, property, shares and crypto, the 60-day property reporting rule and how CGT works inside Self Assessment.
Capital Gains Tax catches people out because it is triggered by events most of us do rarely: selling a second home, cashing in a chunk of shares, or finally converting a crypto portfolio back to pounds. Because it is occasional, the rules feel unfamiliar exactly when a large sum is on the line. And the ground has shifted fast. The annual exempt amount has been cut from GBP 12,300 to just GBP 3,000 in three years, while the rates were overhauled in October 2024, so guidance written even a year ago can be wrong.
This guide covers what actually matters for 2025/26: how a gain is worked out, the current rates, the strict 60-day property reporting rule, how shares and crypto are taxed, and how it all lands in Self Assessment. CGT is its own tax with its own deadlines, so treating it as an afterthought on your annual return is where the penalties begin.
You pay CGT on the gain, not the sale price. If you bought shares for GBP 8,000 and sold for GBP 11,000, the gain is GBP 3,000, not GBP 11,000. From the gain you deduct allowable costs: purchase and sale fees, stamp duty, legal and estate-agent costs on property, and improvement (not maintenance) spending. You then pool any capital losses from the same or earlier years before applying the GBP 3,000 annual exempt amount.
Crucially, your main home is normally exempt under Private Residence Relief, transfers between spouses and civil partners are tax-free, and anything inside an ISA or pension is outside CGT entirely. So CGT mostly bites on second properties, taxable share accounts, funds and crypto.
CGT does not have its own bands. Instead your taxable gains are added on top of your taxable income to decide which rate applies. The portion of gains that falls within your remaining basic-rate band is taxed at the lower rate; anything above is taxed at the higher rate.
| Situation | 2025/26 rate |
|---|---|
| Gains within your basic-rate band | 18% |
| Gains above the basic-rate band | 24% |
| Residential property (second home, buy-to-let) | 18% / 24% (same as above) |
| Business Asset Disposal Relief | 14% (rising to 18% from April 2026) |
| Trustees and personal representatives | 24% |
Since 30 October 2024 the main rates were raised from 10% and 20% to 18% and 24%, so residential property no longer carries a separate higher rate. To see how a gain stacks on top of salary, dividends and other income, the dividends and savings tax calculator is a useful way to map your bands first, since your remaining basic-rate room is what sets your CGT rate. If your tax code looks off after a big disposal year, check it with the tax code checker.
Property is where CGT mistakes get expensive, because of a deadline most people have never heard of. If you sell UK residential property that is not fully covered by Private Residence Relief and there is a taxable gain, you must report it and pay the estimated tax within 60 days of completion through HMRC online CGT on UK property service. This is wholly separate from your Self Assessment return.
This catches landlords selling a buy-to-let, people disposing of an inherited home, and anyone selling a property that was their home for only part of the time they owned it. Even if Self Assessment is months away, the 60-day clock starts at completion, and late filing brings automatic penalties plus interest.
Allowable property costs include the original purchase price, stamp duty paid on buying, legal and survey fees, estate-agent and solicitor fees on the sale, and genuine capital improvements such as an extension or new kitchen. Ordinary repairs and mortgage interest are not allowable against the gain. If you have rental income alongside, the rental income tax calculator handles the income side, while the gain on sale is a separate CGT calculation.
With property the danger is not the rate, it is the calendar. The 60-day report-and-pay deadline runs from completion, long before Self Assessment, and missing it triggers penalties on a gain you have not even filed yet.
Selling shares, units in funds or investment trusts held outside an ISA is a disposal. The complication is working out the cost when you have bought the same shares at different times. HMRC uses share-matching rules: disposals are matched first to shares bought on the same day, then to those bought in the following 30 days (the bed-and-breakfasting rule), and otherwise to a single pooled average cost (the section 104 holding).
Practical points for share investors:
HMRC treats most cryptoassets as property for tax, so disposals fall under CGT rather than Income Tax. A disposal is broader than people expect and includes selling crypto for pounds, swapping one token for another, using crypto to buy goods or services, and gifting it to anyone other than a spouse. Each of these is a separate CGT event, and the same pooling and share-matching rules used for shares apply per token type.
Some crypto activity is instead taxed as income: mining rewards, staking yield, and certain airdrops can be income at the point of receipt, with a later CGT event when you eventually dispose of the tokens. HMRC now receives data directly from exchanges and has been issuing nudge letters to people whose reported gains do not match. The fix is disciplined record-keeping: every transaction, date, value in pounds, and fee. Our dedicated crypto tax guide goes deeper on the income-versus-capital question and nudge-letter responses.
Even where you have already reported a property gain within 60 days, you still report capital gains in the Capital Gains summary pages (SA108) of your Self Assessment return and reconcile the final figure, claiming credit for tax already paid. You must report if your total gains exceed the GBP 3,000 exempt amount, or if your total proceeds exceed a reporting threshold even where the gain is small, or if you want to register a loss to carry forward.
| Asset disposed of | Where to report | Key deadline |
|---|---|---|
| UK residential property (taxable gain) | 60-day UK property service, then SA108 | 60 days from completion |
| Shares, funds, crypto | SA108 Self Assessment pages | 31 January after the tax year |
| Business or business assets | SA108, with any BADR claim | 31 January after the tax year |
| Registering a capital loss | SA108 or written claim | Within four years of the loss |
CGT itself is not part of Making Tax Digital, which only covers trading and property income. But if your self-employment or rental income crosses the MTD thresholds (over GBP 50,000 from April 2026, GBP 30,000 from April 2027, GBP 20,000 from April 2028, all tested on gross income), you will be doing quarterly updates for that income while still filing gains the existing way. Landlords in particular should read our MTD for sole traders guide, since they face both quarterly property reporting and the 60-day CGT rule on any sale.
Take a higher-rate taxpayer who sells a buy-to-let flat bought for GBP 180,000 and sold for GBP 250,000, having spent GBP 12,000 on a genuine extension and GBP 6,000 on buying and selling costs.
Proceeds: GBP 250,000 Less original cost: GBP 180,000 Less improvement (extension): GBP 12,000 Less buying and selling costs: GBP 6,000 Gain: GBP 52,000
Less annual exempt amount: GBP 3,000 Taxable gain: GBP 49,000
As a higher-rate taxpayer the whole taxable gain is charged at 24%: GBP 49,000 at 24% = GBP 11,760 of CGT. Because this is residential property, that figure must be estimated and paid within 60 days of completion, then confirmed on the SA108 pages at year end. Ordinary repairs and the years of mortgage interest already relieved against rental profit do not reduce the gain.
Missing the 60-day property deadline. The biggest single error. The clock starts at completion, not at the 31 January Self Assessment date, and penalties are automatic.
Forgetting token-to-token crypto swaps are disposals. Many investors only count cash-outs, but swapping ETH for another token is a taxable event in pounds at the time of the swap.
Not using both spouses' allowances. Transferring an asset to a spouse before sale is tax-free and unlocks a second GBP 3,000 exemption and potentially a lower rate band.
Confusing improvements with repairs. Only capital improvements reduce the gain; repainting, replacing like-for-like and ongoing maintenance do not.
Losing the allowance by bunching disposals. Selling everything in one tax year wastes future annual exemptions; spreading disposals across years can use several GBP 3,000 allowances.
UK crypto tax explained: when disposals trigger Capital Gains Tax, income vs capital, the £3,000 CGT allowance, record-keeping, HMRC nudge letters and Self Assessment.
UK landlord tax guide: the SA105 property pages, the 20% finance-cost credit on mortgage interest, allowable expenses, the £1,000 property allowance, joint ownership and MTD.
How UK dividend income is taxed in 2025/26: the £500 dividend allowance, 8.75/33.75/39.35% rates, director-shareholder salary-plus-dividends planning and Self Assessment.
How UK residents declare foreign income on SA106: arising vs remittance basis, foreign tax credit relief, overseas rent, dividends and pensions, plus MTD for Income Tax.
Side hustle tax in the UK: the £1,000 trading allowance, when to register, combining a job with self-employment, payments on account and MTD for Income Tax explained.
CIS subcontractor tax explained: reclaiming 20% and 30% deductions through Self Assessment, refunds, gross payment status, verification, allowable expenses and MTD.
TapTax connects to your bank, categorises expenses automatically, and submits quarterly updates to HMRC. Free plan, no card required.
