EIS / SEIS Tax Relief Calculator

How EIS and SEIS reliefs work

EIS and SEIS are HMRC-approved venture capital schemes that give qualifying small UK companies a way to attract investment by offering investors generous tax reliefs. Both come with strict company qualifying conditions (size, age, trade type, no controlling shareholders) and strict investor conditions (must hold for at least 3 years, no connection with the company beyond a small share).

EIS — 2026/27 reliefs

• Income tax relief: 30% of the amount invested, deducted from income tax liability that year (or carried back to the previous year).
• Maximum investment with relief: £1,000,000 per tax year (£2,000,000 if at least £1,000,000 goes into Knowledge Intensive Companies).
• CGT exemption: Any capital gain on disposal after 3 years is entirely free of CGT.
• CGT deferral: Any pre-existing capital gain can be deferred by reinvesting in EIS shares.
• Loss relief: If shares lose value, the loss (after relief received) can be claimed against income or capital gains.
• IHT relief: EIS shares qualify for Business Relief after 2 years, removing them from the IHT estate.

SEIS — 2026/27 reliefs

• Income tax relief: 50% of the amount invested.
• Maximum investment with relief: £200,000 per tax year (raised from £100,000 in April 2023).
• CGT exemption: Same 3-year exemption as EIS.
• CGT reinvestment relief: Half of any capital gain reinvested in SEIS shares is exempt from CGT (a partial deferral, not a deferral-then-payable).
• Loss relief and IHT relief: Same as EIS.

Worst-case downside maths

Take a £20,000 EIS investment for a higher-rate taxpayer:

• 30% income tax relief on £20,000 = £6,000 tax saving
• Net cost after relief: £14,000
• If the company fails (worth £0), the £14,000 loss can be claimed against income at 40% = £5,600 of additional tax saving
• Final downside: £14,000 − £5,600 = £8,400 net cost on a £20,000 investment — the taxpayer has effectively offloaded 58% of the downside risk onto HMRC.

Common mistakes

• Not checking the company has Advance Assurance. A company without HMRC Advance Assurance may turn out not to qualify, retroactively losing reliefs.
• Selling within 3 years. All reliefs are clawed back if shares are sold before 3 years from investment.
• Becoming "connected" with the company. Owning more than 30% of share capital, or being an employee/director (with some exceptions), disqualifies you from the reliefs.
• Forgetting the income tax cap. EIS / SEIS relief can only reduce your income tax liability to zero — it cannot generate a refund of tax you didn't owe.

Related calculators and guides

CGT shares calculator · Dividend calculator · Inheritance Tax calculator · 60% tax trap guide (EIS/SEIS reliefs reduce ANI in the trap).