Do You Need to Report Capital Gains If No Tax Is Due?
You sold some shares, worked out the gain, and it's below £3,000 – so no tax to pay. Does that mean you can forget about it? Not always. HMRC has two separate thresholds that determine whether you need to report, and many people only know about one of them.
The two reporting thresholds
You must report your capital gains through Self Assessment if either of these is true for the tax year:
- Your total taxable gains (after deducting costs but before the annual exempt amount) exceed £3,000
- The total amount you received for all disposals exceeds £50,000, even if your gains are zero or you made a loss
The first threshold is the annual exempt amount (AEA). If your gains are below it, there's no tax to pay – but you may still need to tell HMRC about it.
The second threshold is the one people miss. It's based on proceeds – the total sale value of everything you disposed of – not your profit. Selling £55,000 of shares at no gain still triggers a reporting obligation.
When you don't need to report
You do not need to report if both of the following are true:
- Your total gains are £3,000 or less
- Your total disposal proceeds are £50,000 or less
In that case you don't need to register for Self Assessment or complete the SA108 capital gains pages – unless you already file Self Assessment for another reason (self-employment, rental income, etc).
Three worked examples
Gains below £3,000 and proceeds below £50,000 – Sarah doesn't need to complete the SA108 pages.
No tax to pay, but proceeds exceed £50,000 – James must file Self Assessment and complete the SA108.
Gains exceed the £3,000 AEA. Priya pays 24% on £2,000 (the excess) = £480.
What counts as "proceeds"?
Proceeds means the total amount you received (or were treated as receiving) from all asset disposals in the tax year. This includes:
- Shares and funds sold through a broker
- Assets given away (market value is used as the proceeds)
- Compensation or insurance payouts for lost or destroyed assets
It does not include assets transferred to a spouse or civil partner, or disposals of assets that are exempt from CGT (like your main home or ISA holdings).
What about losses?
If you made a capital loss and want to carry it forward to offset future gains, you must report it – even if both thresholds above are met. You have four years from the end of the tax year to claim a loss. If you don't report it, you lose the ability to use it later.
This is the most common reason to voluntarily report when you don't technically have to. A loss claimed now could save you tax in a future year when you have larger gains.
How to report
If you need to report capital gains, you do so on the SA108 supplementary pages of your Self Assessment tax return. You'll enter your disposal proceeds, allowable costs, and gains for each category of asset (listed shares, unlisted shares, property, and other assets).
If you use our CGT calculator, your report shows the gain and proceeds for every disposal – you can transfer the totals directly to your SA108.
Key dates
| Tax year | Filing deadline (online) | AEA | Proceeds threshold |
|---|---|---|---|
| 2024-25 | 31 January 2026 | £3,000 | £50,000 |
| 2025-26 | 31 January 2027 | £3,000 | £50,000 |
| 2026-27 | 31 January 2028 | £3,000 | £50,000 |
Quick summary
| Situation | Must report? |
|---|---|
| Gains over £3,000 | Yes |
| Proceeds over £50,000 | Yes |
| Want to claim a loss | Yes |
| None of the above | No |
The £50,000 proceeds rule catches a lot of people off guard – especially active traders who make many small trades that individually show little profit but add up to large total proceeds. If in doubt, check your total disposal value for the year, not just your net gain.