See what an angel investor actually gets. Income tax relief at 50% (SEIS) or 30% (EIS), capital gains relief, share loss relief — and the net downside once every relief is applied.
SEIS: earliest-stage companies, trading under 3 years, gross assets not more than £350,000.
Used for share loss relief. Income tax relief itself is 50% (SEIS) or 30% (EIS) regardless of the investor’s band.
2026/27 main rates for gains on shares.
Figures assume the investor has sufficient income tax liability to absorb the relief, holds the shares for the minimum three-year period, and is not connected with the company in a way that denies relief.
SEIS and EIS are the reliefs that most often decide whether a UK angel says yes to a seed round. This SEIS tax relief calculator models the investor’s side of the deal: what they get back immediately, what happens to a reinvested capital gain, and what their real exposure is if the company fails. Founders use it to make the case; investors use it to size a cheque.
Income tax relief is 50% of the amount invested, on up to £200,000 per tax year. The company must be trading for under three years, with fewer than 25 full-time-equivalent employees and gross assets of no more than £350,000 immediately before the share issue, and can raise £250,000 under SEIS in total. SEIS also carries a 50% capital gains reinvestment exemption, full CGT exemption on any gain after three years, and share loss relief. These figures are unchanged for 2026/27.
Income tax relief is 30% of the amount invested, on up to £1,000,000 per tax year (£2,000,000 where at least £1,000,000 goes into knowledge-intensive companies). The 30% rate is unchanged, but the company limits rose sharply from 6 April 2026: annual raise up to £10 million (£20m for knowledge-intensive companies), lifetime up to £24 million (£40m KIC), and gross assets of up to £30 million before the share issue and £35 million after. EIS offers unlimited CGT deferral rather than exemption, CGT exemption on the EIS shares themselves after three years, and loss relief.
The relief figure is the headline; the exposure figure is the argument. Take a 45% additional-rate angel investing £10,000 under SEIS. They receive £5,000 of income tax relief straight away. If the company later fails, share loss relief on the remaining £5,000 at 45% recovers another £2,250 — so the real downside is around £2,750, not £10,000. That is what “we’re SEIS eligible” actually means to an investor: the government has absorbed more than seven-tenths of their risk.
It estimates reliefs from the amounts you enter. It does not test whether the company or the shares qualify — the excluded-trades list, the connection and control tests, the risk-to-capital condition, the sequencing rule between SEIS and EIS shares, and the company’s age, size and gross assets limits all sit outside it. It also assumes the investor has enough income tax liability to use the relief, which is frequently the binding constraint in practice.
Advance assurance is HMRC’s written view that a proposed share issue is likely to qualify. Most angels expect to see it before committing, so in practice it gates the round. The turnaround is HMRC’s, not your adviser’s — typically around four to six weeks — so apply at least eight weeks before a target close. AccTek prepares and submits the application on a two-working-day turnaround from receiving your information; the decision timetable belongs to HMRC.
If you are also modelling innovation reliefs, see the R&D Tax Credit Calculator. To model cash before a raise, use the Startup Runway Calculator. For the full picture on structuring a round, see SEIS advance assurance, EIS advance assurance, SEIS and EIS for startups, our fundraising support service, and our startup accountants.
AccTek is a member firm of the Institute of Certified Practising Accountants (ICPA). Our accountants have a wide range of qualifications and accreditations from trusted professional bodies such as the AAT, ICPA, and ACCA.
