Capital Gains Tax for the 2023/24 tax year applied to disposals made between 6 April 2023 and 5 April 2024. Individuals had a £6,000 annual tax-free allowance, and rates ran from 10% to 28% depending on the asset and your income band.1GOV.UK. Capital Gains Tax Rates and Allowances The online Self Assessment deadline for that year was 31 January 2025, so if you still haven’t filed, penalties are already running and the priority is getting the return in.
Rates and the Annual Exempt Amount
Every individual had £6,000 of gains free of tax in 2023/24. Trusts had £3,000. You only owed CGT on the amount above that threshold.1GOV.UK. Capital Gains Tax Rates and Allowances
For shares, personal possessions, and other non-property assets:
- Basic rate taxpayers: 10%
- Higher or additional rate taxpayers: 20%
For residential property that wasn’t your main home:
- Basic rate taxpayers: 18%
- Higher or additional rate taxpayers: 28%
Which rate applied depended on your income plus the gain. Add your taxable gain on top of your other taxable income for the year. Any part of the gain that sits within your remaining basic rate band is taxed at the lower rate; anything above the basic rate threshold is taxed at the higher rate. A basic rate taxpayer with a large gain can end up paying 10% on one slice and 20% on the next.1GOV.UK. Capital Gains Tax Rates and Allowances
Working Out the Gain
The gain isn’t the sale price. Start with the disposal proceeds (or market value if you gave the asset away or sold it to a connected person) and subtract your allowable costs:
- The original purchase price, plus any fees paid at the time of purchase.
- Buying and selling costs such as estate agent and solicitor fees.2GOV.UK. Tax When You Sell Your Home – Work Out Your Gain
- Money spent on permanent improvements, like an extension. Routine maintenance and decorating don’t count.
Stamp Duty Land Tax paid on the original purchase of a property is deductible as a buying cost. Loan interest and day-to-day upkeep are not. Old receipts matter here: improvement costs from years earlier still reduce the taxable gain if you can evidence them.
A disposal isn’t only a cash sale. Giving an asset away or swapping it counts, and HMRC uses the market value as the deemed proceeds in those cases.
Reliefs That Removed or Cut the Bill
Private Residence Relief on Your Main Home
Selling your only or main home is normally free of CGT under Private Residence Relief. Full relief applies when the property has been your main residence throughout your ownership, you haven’t let any part of it out (a lodger is fine), you haven’t used any part exclusively for business, the grounds are under 5,000 square metres, and you didn’t buy it purely to profit on resale. Where those conditions are met the relief is automatic, with nothing to report.3GOV.UK. Tax When You Sell Your Home Partial relief covers periods and portions that qualify where they’re not.
Transfers Between Spouses and Civil Partners
A transfer between spouses or civil partners who are living together is treated as producing no gain and no loss. The receiver inherits your original cost base, so tax is only due when they sell the asset on to someone else, at which point the gain from the original purchase date becomes taxable in their hands.4GOV.UK. HS281 Capital Gains Tax Civil Partners and Spouses (2024)
This is useful in practice. Shifting an asset to a lower-earning spouse before sale can move the gain from a 20% or 28% rate to 10% or 18%. Both partners also have their own £6,000 exempt amount, so a jointly held asset shelters up to £12,000 for 2023/24.
Business Asset Disposal Relief
If you sold a qualifying business, shares in your personal trading company, or business assets, Business Asset Disposal Relief (formerly Entrepreneurs’ Relief) cut the CGT rate to 10% on qualifying gains up to a lifetime limit of £1 million.5GOV.UK. Business Asset Disposal Relief – Eligibility For share disposals you generally needed at least 5% of the shares and voting rights, to have been an officer or employee of the company, and to have met those conditions for at least two years before the sale.
Using Capital Losses
Losses on disposals during 2023/24 reduce your gains for the same year. Same-year losses must be used in full, even if that takes your remaining gains below the £6,000 exempt amount. You don’t get to hold them back.6GOV.UK. Capital Gains Tax – Losses
Losses brought forward from earlier years work more flexibly: you use just enough to reduce your gains to the annual exempt amount and keep the rest for later. Carried-forward losses can be used indefinitely, but they must be reported to HMRC within four years of the end of the tax year in which they arose. For a 2023/24 loss, that deadline is 5 April 2028. Miss it and the loss is lost.
Reporting Deadlines, and What Late Filing Costs
UK Residential Property: 60 Days
If you sold UK residential property during 2023/24 and owed CGT on it, the gain had to be reported and an estimate of the tax paid within 60 days of completion. That goes through the separate Capital Gains Tax on UK property account, not the annual return. You then also include the gain on your Self Assessment for the year.7GOV.UK. Report and Pay Your Capital Gains Tax – If You Sold a Property in the UK on or After 6 April 2020
Everything Else: Self Assessment
Gains on shares, personal possessions, and other assets are reported on the annual Self Assessment return. For 2023/24 the paper deadline was 31 October 2024 and the online deadline was 31 January 2025.8GOV.UK. Self Assessment Tax Returns – Deadlines
Penalties If You’re Late
Missing the Self Assessment deadline triggers escalating penalties:
- Day 1: an immediate £100 fixed penalty.
- After three months: daily penalties of £10 per day, up to £900.
- After six months: a further penalty of 5% of the tax due or £300, whichever is greater.
- After 12 months: another penalty of 5% of the tax due or £300, whichever is greater.
HMRC also charges late payment interest on any unpaid tax from the date it was originally due.9GOV.UK. Self Assessment Tax Returns – Penalties Separate penalties and interest apply if you also missed the 60-day property deadline. Filing sooner rather than later caps the daily penalty stage and stops interest running on the unpaid amount.
What Has Changed Since 2023/24
The 2023/24 numbers don’t carry forward. The annual exempt amount fell from £6,000 to £3,000 for 2024/25 and remains at £3,000 for 2025/26; the trustee allowance dropped from £3,000 to £1,500.1GOV.UK. Capital Gains Tax Rates and Allowances
From 6 April 2025, the rate structure was simplified. Both residential property and other assets are now taxed at 18% for basic rate taxpayers and 24% for higher and additional rate taxpayers, ending the split that made property gains dearer than share gains.10GOV.UK. Capital Gains Tax – Rates Business Asset Disposal Relief also rose from 10% to 14% for disposals on or after 6 April 2025, with a further increase to 18% planned for April 2026. If you had qualifying business gains in 2023/24, the 10% rate you were entitled to then is more generous than anything on offer now.