SEIS Tax Relief: The Complete Guide for UK Investors

What Is SEIS?

The Seed Enterprise Investment Scheme was introduced in 2012 to encourage individuals to invest in early-stage UK companies. Companies must meet specific qualifying criteria, including being less than three years old, having fewer than 25 employees, and holding gross assets of no more than £350,000. Investors can invest up to £200,000 per tax year into SEIS-qualifying companies and claim a range of tax reliefs on their investment.

The Five SEIS Tax Reliefs

1. Income Tax Relief (50%)

SEIS investors can claim income tax relief of 50% on investments up to £200,000 per tax year. This means a £100,000 SEIS investment effectively costs £50,000 after tax relief. The relief can also be carried back to the previous tax year, providing additional flexibility for tax planning. To retain the relief, shares must be held for a minimum of three years from the date of issue.

2. Capital Gains Tax Exemption

Any gains made on SEIS shares are completely exempt from capital gains tax, provided the shares are held for at least three years and income tax relief has been claimed. This is particularly valuable in the current environment where the annual CGT allowance has been reduced to £3,000 and CGT rates on gains are 18% for basic rate taxpayers and 24% for higher and additional rate taxpayers.

3. CGT Reinvestment Relief

Investors who have realised capital gains elsewhere can reduce their CGT liability by reinvesting into SEIS. Up to 50% of a chargeable gain can be treated as exempt when the full gain amount is reinvested into SEIS-qualifying shares in the same tax year. For a higher-rate taxpayer with a £40,000 gain who reinvests the full amount into SEIS, this could save £4,800 in CGT. SEIS reinvestment relief can also be applied to gains made up to five years after the SEIS investment, or carried back to the previous tax year.

4. Loss Relief

If an SEIS investment fails, the investor can claim loss relief against their income or capital gains. After income tax relief is accounted for, the remaining capital at risk can be offset at the investor’s marginal income tax rate. For a 45% additional rate taxpayer who invested £10,000 and claimed the full 50% income tax relief, the net cost of a total loss would be just £2,750 — meaning 72.5% of the original investment is protected through tax reliefs.

5. Inheritance Tax Relief

SEIS shares qualify for 100% Inheritance Tax (IHT) relief via Business Property Relief (BPR), provided they are held for at least two years and are still owned at the time of death. This is a significantly shorter qualifying period than many other IHT planning tools. From 6 April 2026, 100% IHT relief will be limited to the first £1 million of combined business and agricultural assets, with the remainder eligible for 50% IHT relief (an effective IHT rate of 20%). Any unused allowance can be passed to a surviving spouse.

How to Claim SEIS Tax Relief

Once the SEIS-qualifying company has been issued its compliance certificate by HMRC, investors receive an SEIS3 certificate. This certificate is used to claim relief through the annual self-assessment tax return. Alternatively, investors can request an interim claim to adjust their tax code during the year. The Haatch SEIS Fund aims to process SEIS tax relief claims within an average of two months.

Why Invest Through the Haatch SEIS Fund?

Investing through the Haatch SEIS Fund provides diversification across 10–15 pre-seed B2B SaaS companies, reducing the concentration risk of individual SEIS investments. The fund is managed by operators with £100m+ in personal exits, and is backed by £20m from British Business Bank.

The fund has already delivered multiple profitable exits, including a 7.4x all-cash return on Native Teams, entirely free from capital gains tax.