yCalculator

SEIS / EIS Tax Relief Calculator

Last updated: April 2026

SEISEIS
Relief50%30%
Max/yr£200,000£1,000,000
Company stagePre-revenueGrowing

Investment Details

£

Your income tax rate

How much do you expect to get back per £1 invested in a good scenario?

3.00x

Hold period

If you have an existing capital gain, you can reinvest into SEIS to get 50% CGT relief on that gain.

£

Effective Cost

Investment£20,000
Income tax relief (50%)-£10,000
Effective cost£10,000

A £20,000 investment costs you effectively £10,000

Scenarios

ScenarioGross ReturnNet ProfitMultiple
Total loss£0-£6,000-0.60x
Break-even£10,000£00.50x
2x return£40,000£30,0004.00x
3x return£60,000£50,0006.00x
5x return£100,000£90,00010.00x

Net returns include income tax relief. Gains are CGT-exempt only if qualifying shares are held for at least 3 years.

Relief Summary

Income tax relief£10,000
CGT saving on exit£8,000
SEIS reinvestment relief£0
Total relief value£18,000

Risk perspective

You invested£20,000
Income tax relief received£10,000
Loss relief£4,000
Net loss if total loss£6,000

SEIS/EIS does not eliminate risk. Early-stage investing is high risk. Never invest more than you can afford to lose.

What is SEIS?

The Seed Enterprise Investment Scheme (SEIS) offers 50% income tax relief to investors in very early-stage UK startups. On a £20,000 investment, you receive £10,000 back as income tax relief, making the effective cost £10,000. Gains on SEIS investments are exempt from Capital Gains Tax if held for at least 3 years.

What is EIS?

The Enterprise Investment Scheme (EIS) offers 30% income tax relief on investments up to £1,000,000 per year in qualifying UK companies. EIS companies are typically more established than SEIS companies. Gains are CGT-exempt after 3 years, and losses can be offset against income.

What is the difference between SEIS and EIS?

SEIS is for very early-stage companies, typically pre-revenue or early revenue, with a maximum of 25 employees and £350,000 gross assets. It offers a higher 50% relief rate. EIS covers larger, growth-stage companies with up to 250 employees. It offers 30% relief but allows larger investments of up to £1,000,000 per year.

What is SEIS reinvestment relief?

If you have an existing capital gain, for example from selling shares or property, you can invest up to the gain amount into SEIS and reduce that gain by 50%. So a £50,000 capital gain invested into SEIS reduces your CGT exposure by 50% of £50,000, saving up to £10,000 in CGT at a 20% rate.

Related Finance calculators

finance calculators

Business Loan Repayment Calculator

Calculate monthly repayments, total interest and true cost of a business loan

Calculate →

finance calculators

APR Calculator

Calculate the true annual percentage rate on a loan including interest, arrangement fees, insurance and mandatory charges

Calculate →

finance calculators

Take-Home Pay Calculator

Calculate your exact take-home pay after income tax, National Insurance, student loan and pension deductions

Calculate →