What is the Seed Enterprise Investment Scheme (SEIS)?
The seed enterprise investment scheme offers enhanced tax reliefs for investing in very early-stage companies: 50% income tax relief on qualifying subscriptions, tax-free growth after three years, and generous loss relief. The risk of total loss is correspondingly high.
It sits below EIS in the risk ladder and above it in relief. The company must be genuinely early stage — young, small, and raising within a capped lifetime limit — and the investor's annual subscription is capped well below the EIS limit.
A reinvestment relief exempts part of a capital gain reinvested into SEIS shares, which stacks with the income tax relief. Combined with loss relief, the effective downside for an additional rate taxpayer is a fraction of the amount invested.
None of that changes the underlying reality: most companies at this stage do not succeed. SEIS belongs at the margin of a portfolio, funded from money the investor can afford to lose entirely, and it requires a three-year hold and a company that stays qualifying throughout.