How to Claim a Capital Loss: the 4-Year Deadline and Worthless Shares

What is the deadline for each tax year?

Four years after the end of the tax year of the disposal.¹ The oldest year still open is 2022/23, so a loss from that year needs claiming before 6 April 2027.

How do you claim it?

1. If you file Self Assessment: include the loss on your tax return, on the capital gains summary pages (SA108), with your working.¹⁴
2. If you have never made a gain and are not registered for Self Assessment: you can write to HMRC instead.¹
3. If the loss is from an earlier year still inside the 4 years: you can still claim it now; it then reduces later gains.¹

Keep the records that prove the loss: contract notes or completion statements, the cost, and the costs of buying and selling. See CGT records for what to keep.

How are claimed losses used?

Losses are taken from gains in a set order. Losses from the same tax year are deducted from that year's gains first, in full. Unused losses from earlier years come next, but only to bring your gains down to the tax-free allowance; anything left is carried forward to a future year.¹ Losses from before 5 April 1996 are used after more recent ones.¹

Two restrictions catch people out. You cannot use a loss from giving, selling or disposing of something to a family member or other connected person except against a gain from the same person, and you cannot claim losses on assets given or sold to your spouse or civil partner.¹ The CGT losses guide has the full ordering with a worked example.

How do you claim a loss on worthless shares?

If shares or another asset you still own have become worthless or of "negligible value", you can make a negligible value claim. It treats you as having sold the asset and bought it back at that negligible value, crystallising the loss without a sale.³ You must still own the asset when you claim, and it must have become of negligible value while you owned it.²

• Timing: there is no deadline for the claim itself,³ and you can ask for the loss to be treated as arising at an earlier date, up to 2 years before the start of the tax year in which you claim, if the conditions were met then.² A claim made in 2027/28, for example on a return filed in January 2028, can go back as far as 6 April 2025.
• On the return: enter the loss in the relevant loss box of the SA108 with the code NVC, and send your working showing the loss. The loss only becomes allowable once you notify it.²
• Evidence: HMRC's Shares and Assets Valuation office publishes a list of formerly quoted shares that have been accepted as of negligible value.²

Worked example: a negligible value claim against a fund gain

Tom, a higher-rate taxpayer, paid £8,000 for shares in a listed company that went into administration; they are now worth nothing. In 2026/27 he also sells a fund at a £15,000 gain.

Rates: 24% above the basic-rate band in 2026/27.⁶ Tom makes the claim during 2026/27, or later with an earlier date in 2026/27 when the shares were already worthless, so the loss falls in the same tax year as the gain and is used in full.²

Can a share loss be set against income?

Sometimes. If you subscribed for the shares (bought new shares from the company, not from another investor) in a qualifying trading company, including shares on which you claimed EIS relief, a loss on a sale, negligible value claim, winding up or dissolution can be set against your income instead. The claim is due within one year of 31 January following the tax year of the loss: by 31 January 2029 for a 2026/27 loss. Total income tax reliefs of this kind are capped at £50,000 or 25% of income, whichever is greater, although HS286 says the cap does not apply to losses on EIS or SEIS shares. Any part not used against income stays as a capital loss.²

What happens to losses when someone dies?

Losses in the tax year of death are first set against gains of that year; any surplus can be carried back against the person's gains in the 3 previous tax years, latest year first, and only down to the annual exempt amount for each year.⁵ The personal representatives make the claim. See CGT when someone dies.

Frequently asked questions

This page is general information, not tax advice. Negligible value and share loss claims depend on the company's circumstances; check HS286 or take advice before claiming.