SEIS Loss Relief: How It Cushions a Failed Investment
How SEIS loss relief works when a company fails, with the worked numbers: what a wipe-out really costs at each tax rate.
In this article
SEIS loss relief is the scheme’s safety net. If the company you backed fails, you can set your loss, after the income tax relief you already received, against your income or your capital gains. For a 45% taxpayer, that combination can shrink the real damage of a total wipe-out to roughly 27.5% of what you invested. Here is exactly how it works, with the numbers shown.
How SEIS loss relief is calculated
Your allowable loss is what you paid for the shares minus the SEIS income tax relief you kept minus anything you received on disposal. Because the 50% relief already covered half your money, only the at-risk half can become a loss, and that loss is then relieved at your marginal rate.
The worked example
You invest £10,000. You claimed £5,000 income tax relief up front, so £5,000 is truly at risk. The company fails and the shares are worthless.
- Allowable loss: £10,000 minus £5,000 relief = £5,000
- Loss relief at 45%: £2,250 back
- Total recovered: £5,000 + £2,250 = £7,250
- Real loss: £2,750, or 27.5% of your stake
At 40% the real loss is £3,000; at 20%, £4,000. The cushion scales with your tax rate because the relief is set against income at your marginal rate.
Against income or against gains?
You choose. Setting the loss against income, in the year of the loss or the previous year, usually beats setting it against capital gains, because income tax rates run higher than CGT rates. The claim against income is the feature that makes SEIS and EIS losses unusual; ordinary share losses only offset gains.
When you can claim
On a real disposal at a loss, or, more commonly with failed startups, by making a negligible value claim once the shares are effectively worthless, no need to wait for formal liquidation to finish. The claim goes through Self Assessment, and the loss can be used in the year the shares became worthless or carried back one year.
What keeps the relief alive
The income tax relief you claimed must not have been withdrawn, which mostly means: you did not sell within three years, you did not become connected, and the failure was a genuine commercial failure rather than a scheme unwinding. Keep your SEIS3 and your subscription records; claims are paperwork, and the paperwork is covered in how to claim SEIS relief.
The honest context
Loss relief makes SEIS maths kinder; it does not make failure pleasant. You still lose real money, months of hope, and the alternative uses of both. Treat the cushion as the reason a diversified SEIS portfolio is survivable, not as a reason any single investment is safe. The full picture of the upside sits in how SEIS tax relief works, and the sober reading in the risks of SEIS.
Negligible value claims, properly
Startups rarely die tidily. The company stops trading, the emails stop, and formal liquidation may never be worth anyone’s fees. The tax system anticipates this with the negligible value claim: you assert, with evidence, that your shares have become worth next to nothing while you still own them, and the loss crystallises without a sale. Evidence looks like insolvency correspondence, a strike-off notice, accounts showing the position, or a statement from the directors. The claim can also be backdated up to two years where the shares were already negligible then, which occasionally rescues a relief that would otherwise miss its best year.
Income or gains: choosing with numbers
Take the same £5,000 allowable loss from the example above, this time for a 40% taxpayer who also has £20,000 of capital gains this year taxed at 24%.
- Against income: £5,000 at 40% returns £2,000.
- Against gains: £5,000 at 24% returns £1,200.
Income wins by £800, and usually does, because income tax rates outrun CGT rates. The exceptions are years with little taxable income, or where the income claim would waste allowances, which is exactly the judgement an accountant earns their fee on. You choose income of the loss year or the previous year; whatever the loss cannot absorb falls back into the ordinary capital loss pool for future gains.
Losses inside SEIS funds
A fund holding means you beneficially own a slice of each portfolio company, so relief runs company by company: one holding failing gives you its loss now, regardless of how the rest of the basket performs. Expect the manager to send negligible value confirmations per company, and reconcile them against your SEIS3s before filing. The mechanics of the paperwork side sit in the claiming guide.
What HMRC expects to see
Loss relief claims are routine, and routinely evidenced: your SEIS3 for the original subscription, proof the income tax relief was retained rather than withdrawn, the disposal contract or negligible value evidence, and the arithmetic from subscription to allowable loss. Keep the file from day one, and the claim is an afternoon; assemble it three years later from a dead company’s ashes and it is a month of chasing.
Timing the claim across tax years
A loss is used in the year the disposal or negligible value claim falls, or against the previous year’s income, and that one-year reach is worth planning. If this year’s income is thin, backdating a negligible value claim, where the facts genuinely support it, or simply electing the prior year can move the loss to where your marginal rate is highest. The same file that proves the loss also feeds the prior-year election, so decide the destination before you file rather than amending afterwards.
Common questions
How do I claim SEIS loss relief?
Through Self Assessment, on a disposal at a loss or via a negligible value claim when the shares become worthless. The loss equals your investment minus the income tax relief you kept, and can be set against income or gains.
How much of my SEIS investment can I lose?
With 50% relief up front and loss relief at 45%, a total failure costs an additional-rate taxpayer about 27.5% of the original stake.
Do I lose my 50% relief if the company fails?
No. A genuine commercial failure does not claw back income tax relief already given, and loss relief then applies to the at-risk portion.
