Capital Gains Tax

Capital gains tax · CGT

CGT, calculated properly.

Whether you are selling a buy-to-let, exiting a business, disposing of crypto, or just trying to work out the base cost of shares your dad left you in 1987, we compute, file and plan around capital gains tax with the precision the calculation needs.

60-dayProperty reporting deadline
Up to 24%CGT rate on residential
£3,000Annual exempt amount (2025/26)
BADR14% in 2025/26, 18% from 2026/27

A tax with a hundred edge cases – and we have seen most of them

Capital gains tax sounds simple – sale price minus base cost minus allowable costs, times the rate – until you actually do one. Was the property your main residence at any point? When did the shares vest? Were they part of an EMI scheme? Did you reinvest into EIS? Has there been a takeover, a demerger, or a return of capital since you bought them? Is this a transfer between spouses, or a gift hold-over? And what about the 60-day reporting deadline on UK residential property?

We handle the lot. We track down historic base costs, apply the right reliefs (principal residence relief, lettings relief, BADR, investors\u2019 relief, gift hold-over, rollover, EIS deferral), file the 60-day return on time, and keep you on the right side of HMRC. Where there is a planning angle – timing, spouse transfers, multiple-completion structures – we flag it before you sign.

In your fixed fee

What’s covered

  • Capital gains computations on UK residential property
  • 60-day CGT return filing
  • Capital gains on share disposals
  • Crypto and digital asset disposals
  • Business Asset Disposal Relief (BADR) claims
  • Investors\u2019 Relief claims
  • Principal residence relief and lettings relief
  • EIS / SEIS deferral and reinvestment relief
  • Gift hold-over relief on lifetime gifts
  • Spouse-transfer planning before disposals
  • HMRC enquiry support and disclosures
Why Mercian

Why clients stay

A genuinely modern approach

Cloud accounting, MTD-ready workflows and secure document portals — no shoeboxes of receipts, no surprise emails in March.

Fixed fees, no clock-watching

A clear price agreed up front. Call us as often as you need without worrying about a meter running.

Senior advice, not call-centre answers

Every client has a named accountant who knows your situation — not a ticket queue.

FAQ

Common questions

Do I need to report the sale of my home?
Usually no – principal residence relief covers your only or main home for the period you lived in it. We check whether any of the property qualifies as PRR, and any taxable element gets reported.
What is the 60-day deadline?
For UK residential property disposals creating a gain, you must file a CGT return and pay any tax within 60 days of completion. Miss it and HMRC charges late filing and late payment penalties. We file within the window.
What is BADR worth in 2025/26 and 2026/27?
Business Asset Disposal Relief gives a reduced CGT rate of 14% in 2025/26 and 18% from April 2026, on qualifying disposals up to a £1m lifetime limit. Pre-sale planning matters – timing the disposal correctly can save up to £40k.
I bought shares decades ago – how do I work out the base cost?
For pre-1982 shares the base cost is rebased to 31 March 1982 value. For shares acquired through stock splits, takeovers and rights issues, the calculation gets fiddly. We track it down and document the workings for HMRC.
Do I have to pay CGT on crypto?
Yes – HMRC treats most crypto disposals (sales, swaps, spending crypto) as CGT events. Income tax can apply for staking, mining and airdrops. We compute and file using the share-pooling rules HMRC requires.

Got a disposal coming up? Or one that already happened?

Book a free 30-minute call. We will tell you straight whether we can help, what it would cost, and what to do next. No sales pitch, no obligation.

Try our free CGT calculator

Estimate your Capital Gains Tax in seconds — residential or other assets, with the £3,000 annual exempt amount and current 18% / 24% rates baked in.

Open CGT calculator →