SEIS and EIS give UK investors generous tax reliefs for backing early-stage companies. Enter an investment to estimate your income tax relief, capital gains treatment, loss relief if it fails, and the real cost of the investment. An estimate, not tax advice.
SEIS & EIS Tax Relief Calculator
Estimate the income tax relief, capital gains tax benefit, loss relief and net cost of an SEIS or EIS investment for the 2024/25 tax year.
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How this is worked out
Figures use 2024/25 rules. SEIS gives 50% income tax relief on up to £200,000 invested per year; EIS gives 30% on up to £1,000,000.
SEIS reinvestment relief exempts 50% of a matched capital gain from CGT, valued here at the 20% CGT rate. EIS deferral relief defers the CGT on a matched gain (20% shown): this tax is postponed, not removed, and becomes payable later.
Loss relief assumes the shares become worthless. The allowable loss is your investment minus the income tax relief already claimed, multiplied by your marginal income tax rate. “Net cost if it succeeds” deducts income tax relief (and SEIS CGT saved) from your investment. “Maximum capital at risk” deducts income tax relief and loss relief.
Assumptions: you have enough income tax liability to absorb the relief; the gain is matched within the qualifying investment; the company and shares qualify; loss relief is taken against income at your marginal rate.
Estimate only, not tax or financial advice. Based on 2024/25 rules. The company and shares must qualify and you must have sufficient tax liability to use the relief. Consider professional advice and seek HMRC advance assurance before investing.
Getting the most from this EIS and SEIS calculator
The calculator above estimates the headline reliefs, but a few rules decide whether you actually keep them. Read these alongside your result before you commit to an SEIS or EIS investment.
- Annual limits. SEIS income tax relief is 50% on up to £200,000 invested a year; EIS relief is 30% on up to £1,000,000, or £2,000,000 where the extra goes into knowledge-intensive companies.
- Three-year hold. You must hold the shares for at least three years. Sell or exit sooner and HMRC can withdraw the income tax relief you claimed.
- Carry back. You can elect to treat some or all of an investment as made in the previous tax year, which helps if you paid more income tax then.
- Tax-free growth. As long as the relief conditions are met and the shares are held for three years, any gain when you sell them is free of capital gains tax.
- You need the income tax to relieve. Relief is capped at the income tax you actually owe; it will not create a refund beyond that.
The figures here follow 2024/25 rules and are an estimate, not tax advice. Confirm your own position with an adviser or HMRC before investing.
EIS and SEIS calculator: common questions
What does this EIS calculator work out?
It estimates your income tax relief, the capital gains tax you can defer or exempt, the loss relief if the company fails, and the real net cost of an SEIS or EIS investment for a given amount and marginal tax rate.
How much EIS tax relief can I claim in the UK?
EIS gives 30% income tax relief on up to £1,000,000 invested per tax year, rising to £2,000,000 if at least £1,000,000 goes into knowledge-intensive companies. SEIS gives 50% on up to £200,000.
How long must I hold EIS or SEIS shares?
At least three years from when the shares are issued, or from when the company starts trading if that is later. Selling earlier normally means HMRC withdraws the income tax relief.
Can I carry EIS relief back to the previous year?
Yes. You can elect to treat all or part of the investment as made in the prior tax year, which can be worth more if your income tax bill was higher then.
Is the calculator accurate for my situation?
It is a solid estimate using standard 2024/25 rates, but your actual relief depends on your full tax position and on the company qualifying. Treat it as a guide and check with a tax adviser before investing.