SEIS & EIS Tax Relief Calculator 2026/27

Calculation runs based on standard HMRC rules.

Deductions are calculated and adjusted accordingly.

Frequently Asked Questions & Detailed Tax Guide

What are SEIS and EIS tax reliefs?

The Seed Enterprise Investment Scheme (SEIS) and the Enterprise Investment Scheme (EIS) are highly lucrative tax relief schemes introduced by the UK government to encourage private investment in high-growth, early-stage startups. These schemes offer venture capitalists and angel investors substantial tax incentives to offset the high risks of investing in unquoted companies. For the 2026/27 tax year, SEIS targets seed-stage startups, offering up to 50% income tax relief, while EIS targets slightly larger, early-stage companies, offering 30% income tax relief. Both schemes also offer Capital Gains Tax (CGT) write-offs and inheritance tax exemptions.

What are the core tax benefits for investors?

The investment schemes offer four layers of tax relief:

• Income Tax Relief: SEIS allows you to offset 50% of your investment (up to £200,000 per year) against your income tax bill. EIS allows you to offset 30% of your investment (up to £1,000,000 per year, or £2,000,000 if investing in knowledge-intensive companies).
• CGT Exemption: If you hold the shares for at least 3 years, any capital gains made on the sale of the shares are **100% tax-free**.
• Loss Relief: If the startup fails (which is common), you can claim loss relief. The net loss (investment minus income tax relief) can be offset against your personal income tax or capital gains tax at your marginal rate (up to 45%).
• Capital Gains Reinvestment Deferral: You can defer or obtain capital gains reinvestment relief on existing capital gains by reinvesting the proceeds into EIS/SEIS eligible shares.

Step-by-Step Mathematical Example: SEIS Investment Failure

Let’s calculate the downside protection for an additional-rate (45%) taxpayer investing £20,000 in an SEIS-eligible startup that unfortunately goes bankrupt:

• 1. Initial Investment: £20,000.
• 2. Claim SEIS Income Tax Relief (50%): £20,000 * 50% = £10,000 tax reduction.
• 3. Net cash exposure: £20,000 – £10,000 = £10,000.
• 4. Startup fails (shares become worthless). Gross loss: £20,000.
• 5. Claim SEIS Loss Relief: Offset the net loss against your income tax at 45% marginal rate.
  – Taxable Loss: £20,000 investment – £10,000 tax relief already received = £10,000.
  – Loss Relief tax saving: £10,000 * 45% = £4,500.
• 6. Total tax savings: £10,000 (upfront) + £4,500 (loss relief) = £14,500.
• 7. Actual Net Loss: £20,000 investment – £14,500 tax savings = £5,500 net loss.
• 8. Maximum downside is capped at just **27.5%** of the original investment, despite the startup failing completely!

Tax Expert Pro-Tips: Advanced Assurance for Founders

David Vance, CTA FCA, recommends: “For founders raising capital, having SEIS/EIS status is vital to attracting angel investors. You should always apply for ‘Advance Assurance’ from HMRC before launching your funding round. This is an official document from HMRC confirming that your company meets the qualifying criteria. Investors will rarely transfer funds without seeing this assurance. Keep in mind that companies must not have gross assets exceeding £350k for SEIS, or £15m for EIS, and must operate in a qualifying trade (excluding financial services, leasing, or property development).”

Legislative References

• Income Tax Act 2007 – Part 5 (Enterprise Investment Scheme) and Part 5A (Seed Enterprise Investment Scheme).
• HMRC Venture Capital Schemes Manual (VCM10000) – Advance assurance and qualifying trade guidelines.