The Seed Enterprise Investment Scheme gives you Income Tax relief of 50% on new shares in qualifying companies, and can make half of a reinvested gain free of Capital Gains Tax. Enter your investment and tax bill to see what you get back and what the shares really cost.
Shares issued in 2026/27
SEIS relief is 50% of the amount you subscribe for new shares in a qualifying company, taken off your Income Tax bill. You can claim on up to £200,000 a tax year, so the most relief in one year is £100,000. The relief can't be more than the Income Tax you pay, and any excess is lost. You can treat some or all of the shares as issued in the previous tax year and claim there instead, within that year's £200,000 limit.
| Seed Enterprise Investment Scheme | Rule |
|---|---|
| Income Tax relief | 50% |
| Most you can invest with relief | £200,000 a tax year |
| Minimum holding period | 3 years |
| CGT reinvestment relief | 50% of the investment, up to £100,000 of gains |
| CGT on your gain when you sell | None after 3 years, if you got Income Tax relief |
| Relief for losses against income | Yes |
If you sell any asset at a gain and reinvest all or part of the gain in SEIS shares, you can treat up to half of the gain as exempt from Capital Gains Tax. To get the full relief you must invest at least as much as the gain; if you invest less, the relief is limited to half the amount invested. The most you can claim is £100,000, and you only get reinvestment relief if you also get SEIS Income Tax relief on the shares.
HMRC's example: you have a £15,000 gain and invest £14,000 in SEIS shares in the same tax year with full Income Tax relief. You can claim reinvestment relief on £7,000, so the chargeable gain falls to £8,000 before your annual exempt amount.
You pay no Capital Gains Tax on a gain when you sell SEIS shares after holding them for at least 3 years, as long as you received the Income Tax relief and none of it was withdrawn. If you sell within 3 years, some or all of the relief is withdrawn. If you make a loss, you reduce the cost of the shares by the Income Tax relief you kept: HMRC's example of £100,000 invested, £20,000 of relief kept and a sale for £60,000 gives a £20,000 loss. SEIS losses can be set against income as well as gains.
Work out the tax on your gains with the Capital Gains Tax calculator or the CGT on shares calculator, and see your Income Tax bill with the Income Tax calculator. If you run the company yourself, the Corporation Tax calculator shows its side.
50% of the amount you invest, taken off your Income Tax bill, on up to £200,000 a tax year. That is up to £100,000 of relief, but no more than the Income Tax you pay.
If you reinvest a gain in SEIS shares, up to half of the gain is exempt from Capital Gains Tax, limited to half the amount invested and to £100,000 in total. You must also get SEIS Income Tax relief on the shares.
Yes. You can treat some or all of the shares as issued in the previous tax year and claim the relief against that year's Income Tax, within that year's limit.
Yes. You can get SEIS tax relief if you're a director of the company. You can't claim if you or an associate is an employee, or if you hold a substantial interest of more than 30%.
At least 3 years. If you sell within 3 years, some or all of the Income Tax relief is withdrawn.
You can claim a loss, working it out after reducing the cost of the shares by the Income Tax relief you kept, and set it against your gains or your income.
