SEIS vs EIS: which one your startup actually needs
Two UK tax schemes that look similar on the surface. Pick the wrong one — or run them in the wrong order — and your investors lose their relief. Here is the decision in sixty seconds, then the detail.
The sixty-second answer
SEIS is for your first £250,000. Your company must be under three years old, have fewer than 25 staff, and hold under £350,000 in gross assets. Investors get 50% income tax relief.
EIS is for everything after that — up to £10m a year, £12m over the company's lifetime (£20m if you qualify as knowledge-intensive). Investors get 30% income tax relief.
Most qualifying companies use both: SEIS for the first pre-seed cheque, then EIS for seed and Series A. The order matters — see "The sequencing trap" below.
SEIS vs EIS — side by side
| SEIS | EIS | |
|---|---|---|
| Maximum raise | £250,000 per company, lifetime | £10m per year · £12m lifetime (£20m for KICs) |
| Company age | Under 3 years trading | Under 7 years trading (10 for KICs) |
| Employees | Fewer than 25 FTE | Fewer than 250 FTE (500 for KICs) |
| Gross assets (pre-investment) | Under £350,000 | Under £30m |
| Investor income tax relief | 50% | 30% |
| Annual investor limit | £200,000 | £1m (£2m if at least £1m in KICs) |
| CGT exemption on exit | Yes, after 3 years held | Yes, after 3 years held |
| Loss relief if company fails | Yes, on net investment | Yes, on net investment |
| CGT reinvestment relief | 50% exempt | 100% deferred |
| IHT business relief | After 2 years held | After 2 years held |
Limits reflect rules from 6 April 2026, including the EIS annual investment increase from £5m to £10m and the gross asset limit move to £30m.
Pick SEIS when…
- You are pre-revenue or sub-£200k revenue. The £350k gross assets cap is easy to breach the moment you take meaningful investment, so SEIS has to happen first.
- You are raising £250k or less. Below this number, the extra 20% relief makes SEIS materially easier to sell to angels. Above £250k, you cannot use it anyway.
- You incorporated within the last three years. After 36 months of trading you are out — even if you have only raised friends-and-family money up to that point.
Pick EIS when…
- You have already issued SEIS shares and spent the funds, or you never qualified for SEIS in the first place.
- You are raising more than £250,000. EIS scales: a single round can take £10m, the lifetime cap is £12m (£20m for KICs).
- You qualify as knowledge-intensive. 15%+ of opex on R&D in at least one of the last three years is the most common way in. Declare it — the rules are materially better.
The sequencing trap
The single most expensive mistake founders make: issuing EIS shares before SEIS shares are issued and the SEIS money is spent on qualifying trade. The penalty is brutal — HMRC withdraws all SEIS relief from those investors.
Practically, this means closing your SEIS round, spending the money on qualifying activities (people, R&D, marketing — not buying property or paying off shareholder loans), and only then issuing the first EIS shares. Trying to do a "combined SEIS/EIS round" that closes in a single day is a recipe for disqualification unless every share is issued, allotted, and recorded in the correct sequence on the correct dates.
If you have an investor offering a £400k cheque and your SEIS allowance is £250k, the right structure is SEIS first for £250k, deploy, then EIS for the remaining £150k. Not the other way round.
What disqualifies you outright
Even if your size and age are fine, certain trades make you ineligible. HMRC reads the excluded activities list strictly:
Borderline cases — a software company with an IP licensing arm, a clinic with a property-holding subsidiary — get decided by HMRC on the facts. If you are uncertain, do not guess; get a written opinion before you apply.
Advance assurance: when to start
Advance assurance is HMRC's confirmation that, based on what you have shown them, your company looks like it qualifies. It is not a guarantee — HMRC can still investigate after the raise — but it is the document angels and angel networks will ask for before committing.
The application takes six to eight weeks on a clean run, longer if HMRC has questions. Start it before you start pitching, not after. Founders who wait until they have a term sheet in hand lose six weeks at the worst possible moment — when investor enthusiasm is at its peak and most likely to cool.
A complete application needs your business plan, a three-year financial forecast, the latest accounts (or opening balance sheet if newly incorporated), details of any existing shareholders and previous investment, and the proposed share structure. Missing any of these triggers a rejection rather than a delay.
Raising in the next six months?
Stertha Advisory handles SEIS and EIS advance assurance applications end to end — eligibility review, HMRC submission, follow-up correspondence, and the compliance certificates investors need to claim their relief after the raise closes. We have done this for software, biotech, fintech and consumer companies across the UK.
Common questions
Want the long-form read?
EIS vs SEIS: which scheme should your startup target in 2026? (7 min read)