EIS Tax Relief Calculator 2025/26
Calculate income tax relief on EIS and SEIS investments, CGT deferral and reinvestment relief, and see what you actually lose if the company fails. All figures use HMRC 2025/26 rates.
Try another scenario
How to Use This Calculator
EIS Tax Relief tab
Enter your EIS investment amount, income tax band, and any capital gain you want to defer. The calculator shows your 30% income tax relief, the net cost of your investment, and the CGT deferred. Expand "More options" to indicate if the company is a knowledge-intensive company (KIC), which raises the annual limit from £1,000,000 to £2,000,000.
SEIS Relief tab
Enter your SEIS investment amount (max £200,000/year), tax band, and any capital gain to reinvest. See your 50% income tax relief and the 50% CGT reinvestment relief, which exempts half of any reinvested gain from CGT. The calculator shows your total tax benefit and effective cost of investment after all reliefs.
If It Goes Wrong tab
The worst case: the company fails and your shares are worth £0. This tab calculates exactly how much you actually lose after factoring in the initial income tax relief you already claimed and the additional loss relief available. Higher and additional rate taxpayers recover a larger percentage of their investment through loss relief.
Share your result
Every input is encoded in the URL. Click Share to send your exact scenario to a financial adviser, co-investor, or save it for later.
The Formula
EIS and SEIS relief calculations follow HMRC rules:
Relief = Investment × 30%
Max relief: £300,000/year (£1M × 30%) or £600,000 for KICs (£2M × 30%)
SEIS Income Tax Relief
Relief = Investment × 50%
Max relief: £100,000/year (£200,000 × 50%)
SEIS CGT Reinvestment Relief
Exempt gain = min(Capital Gain, SEIS Investment) × 50%
CGT saved = Exempt Gain × CGT Rate (18% or 24%)
EIS CGT Deferral
Deferred CGT = Capital Gain × CGT Rate
(Payable when EIS shares disposed of, unless rolled into another EIS)
Loss Relief (company fails, shares = £0)
Allowable Loss = Investment − Income Tax Relief Received
Loss Relief = Allowable Loss × Marginal Income Tax Rate
Net Loss = Investment − Initial Relief − Loss Relief
The key insight: even in the worst case (total company failure), a higher rate taxpayer investing via EIS loses around 42p per £1 invested, not £1. For SEIS, it is closer to 27.5p per £1. This is because the combination of upfront income tax relief and loss relief significantly cushions the downside.
Example
Sarah — Consultant, Higher Rate Taxpayer, London
Sarah earns £95,000 and has a £120,000 capital gain from selling a buy-to-let property. She invests £100,000 in an EIS-qualifying tech company and £50,000 in an early-stage SEIS company.
EIS Tax Relief tab
Sarah gets £30,000 off her income tax bill immediately and defers £28,800 in CGT. Her £100,000 investment effectively costs £70,000 after income tax relief, with the CGT payment pushed to whenever she sells the EIS shares.
If It Goes Wrong tab
If the EIS company fails completely:
Even in the worst case, Sarah's actual loss is £42,000, not £100,000. She recovers 58% of her investment through tax reliefs.