SEIS Guide 2026/27: 50% Income Tax Relief on Early-Stage Investments
SEIS offers 50% income tax relief on up to £200,000 invested per year in qualifying early-stage companies. Learn CGT exemptions, loss relief, and reinvestment relief in 2026/27.
The Seed Enterprise Investment Scheme (SEIS) offers some of the most generous tax incentives available to UK investors. A 50% income tax reduction on investments up to £200,000 per year, combined with full CGT exemption on exits and valuable loss relief on failures, makes SEIS a compelling tool for higher-rate taxpayers who are comfortable with the risks of investing in early-stage companies. Following the doubling of the annual investment limit from £100,000 to £200,000 in April 2023, SEIS has become even more impactful for serious angel investors.
How SEIS income tax relief works
SEIS income tax relief is claimed against your income tax liability -- not deducted from income. This is an important distinction:
- Income tax deduction reduces the income on which tax is calculated.
- Income tax relief directly reduces the tax bill.
So SEIS relief of 50% on a £20,000 investment = £10,000 directly off your income tax bill. If your income tax for the year is £30,000, it is reduced to £20,000.
Key conditions on the relief:
- You must have a UK income tax liability sufficient to absorb the relief. The relief cannot create a tax repayment beyond zero liability.
- The shares must be held for at least 3 years from the date of issue (or the date the company first commences trading, if later) for the relief to be retained.
- If you dispose of the shares within 3 years, the income tax relief is withdrawn and must be repaid to HMRC.
- The investor must not be connected with the company -- broadly, holding more than 30% of its ordinary share capital or being an employee (though being a director is allowed).
The £200,000 annual limit and carry-back
You can invest up to £200,000 in SEIS shares in a single tax year and claim 50% relief -- a maximum income tax reduction of £100,000 per year.
Additionally, you can elect to treat all or part of an investment made in one tax year as if it were made in the prior tax year. This carry-back allows you to claim relief against a prior year's income tax if:
- The current year's tax liability is too low to fully utilise the relief.
- You want an immediate refund of prior year tax rather than waiting for the current year's return.
Carry-back does not require you to have made the investment in the prior year -- the election simply treats it as if you had.
CGT exemption: the compounding benefit
If you sell SEIS shares after holding them for at least 3 years and the income tax relief has not been withdrawn, any capital gain on the disposal is completely exempt from CGT. There is no limit on the gain that can be exempted.
Example: You invest £20,000 in an SEIS company in 2023. In 2026 (three years later), the company is acquired for £200,000 -- a gain of £180,000 on your holding. This entire £180,000 gain is exempt from CGT. You also received £10,000 income tax relief when you invested.
Total tax-free benefit:
- Income tax relief (received upfront): £10,000.
- CGT exemption on exit gain: £180,000 x 20% (if higher rate) = £36,000 CGT avoided.
- Total tax benefit: £46,000 on a £20,000 investment.
CGT reinvestment relief: a one-off additional benefit
A separate benefit -- available once only per investor -- allows you to reduce a capital gain by reinvesting in SEIS. If you have a capital gain from any asset (shares, property, business sale) and invest proceeds into SEIS shares:
- 50% of the reinvested amount is exempt from CGT in the year of reinvestment (or the following year if carry-back is used).
Example: You sell a buy-to-let property making a gain of £80,000. You reinvest the full £80,000 in SEIS companies in the same tax year. CGT reinvestment relief = 50% x £80,000 = £40,000 exempt. The remaining £40,000 gain is taxable (less the £3,000 AEA). Without the relief: £77,000 taxable at 24% = £18,480 CGT. With the relief: £37,000 taxable at 24% = £8,880 CGT. Saving: £9,600 CGT.
This reinvestment relief applies in addition to the income tax relief on the SEIS investment itself.
Loss relief: the downside protection
Venture capital investments fail. SEIS has built-in loss relief to reduce the effective risk:
Calculating the allowable loss:
If an SEIS investment fails to zero, the allowable loss for income tax purposes is: Net cost = Investment amount - SEIS income tax relief already received
For a £10,000 investment with 50% relief: net cost = £10,000 - £5,000 = £5,000.
This £5,000 can be offset against income (not capital gains) in the year of failure, or carried back 1 year. For a higher-rate (40%) taxpayer, this saves £2,000 in income tax, reducing the net loss to £3,000 from the original £10,000 investment.
Effective downside:
- Invest £10,000 in SEIS. Receive £5,000 income tax relief immediately.
- Investment fails.
- Claim loss relief on net cost of £5,000 at 40%: saves £2,000.
- Net out-of-pocket loss: £3,000 on a £10,000 investment (30% effective loss).
If the investment succeeds, the upside is fully sheltered from CGT.
SEIS vs EIS: the key differences
| Feature | SEIS | EIS |
|---|---|---|
| Income tax relief | 50% | 30% |
| Annual investor limit | £200,000 | £1,000,000 (up to £2m for knowledge-intensive) |
| CGT exemption | Yes (3 years) | Yes (3 years) |
| CGT deferral | No | Yes |
| Company age | Under 3 years | Under 7 years (10 for knowledge-intensive) |
| Max company raise | £250,000 | £5,000,000/year |
| Company employees | Under 25 | Under 250 |
SEIS is always for the earliest stage -- the first money in. Once a company has used its SEIS allowance, subsequent investment rounds use EIS.
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Open Income Tax calculatorFrequently asked questions
What is SEIS?
The Seed Enterprise Investment Scheme (SEIS) is a UK government scheme that provides significant tax incentives for individual investors who invest in small, early-stage companies. Investors receive 50% income tax relief on investments of up to £200,000 per tax year, plus exemptions from Capital Gains Tax and loss relief on failed investments.
How much income tax relief does SEIS provide?
SEIS provides 50% income tax relief on qualifying investments of up to £200,000 per tax year. If you invest £10,000 in an SEIS-qualifying company, you can reduce your income tax bill by £5,000. The relief is available against the current tax year's income tax liability, or it can be carried back to the prior tax year. The investment limit was doubled from £100,000 to £200,000 in April 2023.
What are the qualifying conditions for a company to offer SEIS?
For a company to offer SEIS, it must: have gross assets under £350,000 before the investment; have fewer than 25 full-time equivalent employees; have been trading for less than 3 years (or not yet started trading); have raised no more than £250,000 under SEIS previously; and be a qualifying trade (most commercial trades qualify -- excluding financial services, property development, legal and accountancy services, and certain others).
Is the gain on an SEIS investment exempt from CGT?
Yes. Gains on SEIS shares held for at least 3 years are completely exempt from Capital Gains Tax, provided the SEIS income tax relief was not withdrawn. There is no requirement to reinvest the gain -- it is simply free of CGT. This is a significantly more generous CGT exemption than EIS (which also has a CGT exemption but at a lower income tax relief rate).
What is the SEIS CGT reinvestment relief?
SEIS also offers a one-off CGT reinvestment relief: if you make a capital gain on any asset and reinvest 50% of the gain into SEIS shares in the same tax year or the following year, 50% of the reinvested gain is exempt from CGT. For example, a £50,000 capital gain reinvested entirely in SEIS: £25,000 of the original gain becomes exempt from CGT. This is a separate and additional benefit to the income tax relief.
What loss relief is available on failed SEIS investments?
If an SEIS investment fails, the investor can claim loss relief. The allowable loss is calculated after deducting the income tax relief already received (so the effective loss = investment minus income tax relief). This loss can be offset against income in the same year or carried back 1 year. For a 45% additional-rate taxpayer who invested £10,000 and received £5,000 SEIS relief, the maximum effective loss (net cost) is £5,000, of which 45% = £2,250 can be recovered as income tax relief -- leaving a net loss of just £2,750. The original £5,000 SEIS income tax relief was already received.
Can I claim SEIS relief if I also want to subscribe for EIS shares in the same company?
No -- you cannot have both SEIS and EIS relief in the same company. However, after a company has raised its maximum SEIS amount (£250,000), it can apply to HMRC for EIS status and subsequent investors (or the original investors making further investments) can use EIS. SEIS is always for the earliest funding rounds; EIS is for the next stage of growth.
How do I claim SEIS income tax relief?
The company must obtain SEIS advance assurance from HMRC before raising the investment, and then file an SEIS1 compliance statement with HMRC after shares are issued. HMRC then issues SEIS3 certificates to investors. Investors include the investment amount on their self-assessment tax return and attach the SEIS3. The 50% relief is applied against the income tax liability for the relevant year.
Can SEIS relief be carried back to the prior tax year?
Yes. You can carry back up to the full annual investment (£200,000) to the prior tax year, claiming the 50% income tax relief against the prior year's tax liability. This is useful if your current year's income tax liability is too low to absorb the full relief, or if you made the investment early in the tax year and want to get the relief faster by applying it to the prior year's return.
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