SEIS tax relief calculator
SEIS stands for the Seed Enterprise Investment Scheme.
SEIS gives investors 50% income tax relief on shares in qualifying very young companies, on up to £200,000 a year.
The formula
SEIS = amount invested × 50% income tax relief
Worked example: £10,000
The example uses the guide's seed round, £200,000 for 20%, with a matching cap table, exit, fund and market.
- £20,000 × 50% = £10,000 off the investor's income tax bill
- Net cost £20,000 − £10,000 = £10,000
Work out your SEIS
Until you type a figure, the results show an example business. Fill in only what you know: from then on every result uses your figures alone, and nothing you type leaves your browser.
SEIS relief for the example
Example£10,000
- £20,000 × 50% = £10,000 off the investor's income tax bill
- Net cost £20,000 − £10,000 = £10,000
- Relief cannot be more than the income tax the investor owes for the year.
Formula: Amount invested × 50% income tax relief.
- Net cost
- £10,000
- Hold for at least
- 3 years
- or relief can be taken back
Everything your numbers show
For the example business: 27 of 27. Type your own figures to replace them. Select one for its page.
- Valuation£1,000,000post-money
- Pre-money valuation£800,000
- Post-money valuation£1,000,000
- Equity20.0%Equity sold
- Dilution70.0%kept by existing shareholders, down from 100.0%
- Option pool142,857new pool shares
- Fully diluted60.0%Fully diluted ownership
- SAFESimple agreement for future equity89,286shares
- Loan note96,429shares
- Pro rata rights£200,000Pro rata amount
- Liquidation preference£1,000,000to the investor
- Vesting180,000after 18 months
- Cliff120,000at month 12
- SEISSeed Enterprise Investment Scheme£10,000
- EISEnterprise Investment Scheme£6,000
- VCTVenture capital trust£4,000
- TAMTotal addressable market£240,000,000a year
- SAMServiceable available market£60,000,000a year
- SOMServiceable obtainable market£3,000,000a year
- Down roundDown round
- Up roundDown round
- Flat roundDown round
- MOICMultiple on invested capital2.80x
- IRRInternal rate of return22.9%a year
- TVPITotal value to paid-in capital1.50x
- DPIDistributions to paid-in capital0.40x
- Dry powder£24,000,000
How to read your result
The net cost is what the investment really costs the investor after relief, which is why SEIS helps founders raise a first round.
Watch out for
Relief can be taken back if the investor sells within three years or the company stops qualifying. Get HMRC advance assurance before you pitch.
Last checked . Estimates only, not financial, tax or legal advice: check your accounts and documents, and take advice before you act. More terms in the startup glossary.