SEIS and EIS advance assurance: what it is and how to get it
S/EIS advance assurance help you to attract investment into your business. This guide gives you the introduction you need to secure it.
In Short
SEIS and EIS advance assurance is HMRC's upfront confirmation that your company and the shares you plan to issue should qualify for Seed Enterprise Investment Scheme (SEIS) or Enterprise Investment Scheme (EIS) tax relief. It's not legally required, but most UK angel investors expect to see it before they commit.
To apply, you need to be incorporated, have a clear pitch deck, 3 year + financial forecasts, your articles of association, investment agreement and the contact details of at least one potential investor. You submit via HMRC's online service and most decisions come back in 15–40 working days.
From 6 April 2026, the EIS limits doubled, companies can now raise up to £10 million a year and £24 million over their lifetime under EIS, which changes the game for larger rounds.
What is SEIS and EIS advance assurance?
SEIS and EIS advance assurance is HMRC's non-binding view that, based on the information you've submitted, your proposed share issue should qualify for relief under the Seed Enterprise Investment Scheme or the Enterprise Investment Scheme. It doesn't guarantee tax relief, and it doesn't commit HMRC to anything binding, but it's the single piece of paper most UK angels want to see before they wire money.
The schemes themselves are government programmes designed to funnel private capital into early-stage UK businesses. They work by offering meaningful tax reliefs to the individuals who back eligible companies. Advance assurance is how you signal, before the round closes, that those reliefs are likely to be available.
In practice, it's a trust document. Investors see it and relax. Without it, many angels will politely pass, or ask you to come back when you've got it.
SEIS vs EIS: what's the difference?
The two schemes sit on a spectrum. SEIS is for the absolute earliest stage. EIS is for companies that have moved beyond it. Both can be used by the same company, usually in sequence.
| SEIS | EIS (from 6 April 2026) |
Who it's for | Very early-stage, newly incorporated companies | Slightly more established, up to 7 years from first commercial sale |
Company age limit | Under 3 years | Under 7 years (10 for knowledge-intensive companies) |
Maximum raise | £250,000 lifetime | £10 million per year, £24 million lifetime (£20m/£40m for KICs) |
Investor tax relief | 50% of income tax | 30% of income tax |
Max per investor | £200,000 per tax year | £1 million per tax year (£2m if £1m in KICs) |
# of employees | Under 25 | Under 250 (500 for KICs) |
Gross assets | Under £350,000 | Under £30m before / £35m after the raise |
Most founders start with SEIS and move to EIS as they grow. You can run both, but you cannot issue SEIS shares after EIS shares, SEIS always comes first, and the share issues must be on different days.
What changed on 6 April 2026?
If you've read older guidance on EIS, you may have seen lower limits. They changed. As part of the 2025 Autumn Budget, the government doubled the EIS company funding caps for shares issued on or after 6 April 2026:
Annual raise: £10 million (previously £5 million)
Lifetime cap: £24 million (previously £12 million)
Gross asset limit: £30 million pre-issue (previously £15 million)
Knowledge-intensive companies (KICs): £20m annual, £40m lifetime
The SEIS caps are unchanged. The Venture Capital Trust rate of income tax relief dropped from 30% to 20% in the same round of changes. If you're building projections or briefing investors, make sure your numbers reflect the post-April 2026 regime.
Why advance assurance matters: the investor's perspective
Advance assurance changes the maths for an investor. It directly reduces the after-tax risk they're taking on when they back you, which is why experienced angels treat it as table stakes.
The numbers are worth spelling out.
A £10,000 SEIS investment effectively costs the investor £5,000 after 50% income tax relief. They pay no capital gains tax on any uplift if they hold the shares for three years or more. If the company fails, loss relief at their marginal tax rate softens the downside further.
A £10,000 EIS investment works the same way at a lower rate. The investor claims £3,000 back against their tax bill. Any gain after three years is CGT-free. They can defer gains from elsewhere by reinvesting into EIS shares. Loss relief applies if things go wrong.
Without advance assurance, none of that is on the table for the investor until you file a compliance statement after the round, which means they're taking full equity risk on the hope that the relief will come through. With assurance in place, your round looks materially more attractive.
What you need in place before you can apply
You must be incorporated before you can apply for advance assurance. HMRC issues assurance to a specific registered entity, so there is no route to apply before you have a company number. If you haven't incorporated yet, that's step one.
Beyond incorporation, the application is more substantial than many founders expect. You'll need documents across four categories:
1. HMRC's online application form
Submitted via your Government Gateway account. Only a director, company secretary, trustee or authorised agent can submit it. The form asks detailed questions about your trade, funding plan, share rights, group structure and risk-to-capital condition.
2. Your fundraising materials
A pitch deck and a three-year financial forecast. HMRC reads these properly, vague projections, unexplained revenue assumptions or a deck that doesn't match your form answers will cause delays or rejection. Treat it like an investor pitch, not a tick-box exercise.
3. Your legal funding documents
Your articles of association and, where relevant, your subscription and shareholders' agreement. If your articles contain preference rights, anti-dilution provisions or other terms that go beyond ordinary shares, HMRC will scrutinise them, some common clauses disqualify shares from relief.
4. Supporting documentation
Your most recent accounts (if you have them), your memorandum of incorporation, a copy of your register of members, and the names and addresses of at least one (ideally two) potential investors. If you're raising through a crowdfunding platform or fund manager, you'll provide a letter of engagement instead.
How to apply for SEIS and EIS advance assurance: the process
The process follows a clear sequence. Start earlier than you think you need to.
Incorporate your company. You cannot apply without a registered company.
Check eligibility. Confirm your trade is qualifying (some activities, property development, financial services, farming among them, are excluded), that you're within the age, asset and employee limits, and that you meet the risk-to-capital condition.
Prepare your pack. Deck, forecast, articles, shareholder agreement, memorandum, accounts, investor details. Save everything as PDFs before you log in.
Submit via HMRC's online service. Find it at gov.uk. Note the temporary access key when you start so you can pause and return.
Respond to HMRC queries. The Venture Capital Reliefs team may come back with questions. Answer fully and quickly.
Receive your assurance letter. This is what you share with investors. You can cite it in your pitch deck and term sheet.
Close the round and file compliance. Once shares are issued and you've spent at least 70% of funds, submit SEIS1 or EIS1 to HMRC. They then issue SEIS3/EIS3 certificates that your investors use to claim relief.
How long does SEIS/EIS advance assurance take?
HMRC aims to deal with 80% of correspondence within 15 working days and 95% within 40 working days. In practice, straightforward applications often come back in 3–4 weeks. Complex applications (group structures, KIC status, unusual trades, bespoke share rights) can take 6–8 weeks or more, especially at peak periods around the end of the tax year.
The practical implication is the same either way: start early. Waiting until you're in live investor conversations to apply introduces friction at exactly the stage when momentum matters most.
Common pitfalls to avoid
Most rejections and delays come from a small set of recurring mistakes.
Incomplete submissions
Missing attachments, half-answered questions, inconsistent dates between your form and your deck. HMRC will either ask for more information (adding weeks to the timeline) or decline to opine. Go through the checklist twice before you submit.
No investor details
HMRC requires the contact details of at least one named potential investor with every submission. Most advisors recommend listing two. This is non-negotiable and easy to miss if you go in cold.
Exit-focused language in your deck
Phrases like "aiming to exit within three years via acquisition" can cause HMRC to pause. The schemes are designed to support long-term growth. Anything that implies a short-term flip or a pre-arranged exit can complicate your application. Frame your plan around growth and product development, not liquidity events.
Non-qualifying share rights
If your articles give investors preferential dividends, pre-set redemption rights or guaranteed returns, the shares may not qualify, the risk-to-capital condition requires real equity risk. Have a solicitor review your articles before you submit.
Testing the limits
HMRC declines to opine on speculative applications or ones that appear to be testing the boundaries of the rules. If you're unsure whether a particular activity qualifies, get advice before you apply, not after.
A practical next step: get expert support
Getting advance assurance can be tricky the first time around. The application pulls together legal documents, a credible pitch, financial projections and technical knowledge of a tax scheme most founders have never interacted with before. A delayed or rejected application costs real time during fundraising, time you can't afford when investor conversations are already in flight.
Our advice: do it with expert support.
FOUNDRS has partnered with FounderCatalyst, a specialist platform that helps UK startups get their SEIS and EIS advance assurance in place and manage the legal side of funding rounds. They handle the application end-to-end, from eligibility check and document preparation through to HMRC correspondence and post-round compliance.
All FOUNDRS users get a 5% discount on FounderCatalyst's services, covering both advance assurance and funding legals. It's part of how we support founders from incorporation through to their first round, and every stage after.
Frequently asked questions
Is SEIS/EIS advance assurance mandatory?
No. It's a discretionary, non-statutory service from HMRC and there is no legal requirement to have it. In practice, most UK angel investors and early-stage funds expect to see it before they commit, which makes it close to mandatory for almost any real round.
How much does SEIS/EIS advance assurance cost?
There is no HMRC application fee, applying direct is free. Costs come from professional support: a specialist platform like FounderCatalyst or an accountant typically charges a few hundred to a few thousand pounds to prepare and submit on your behalf, depending on complexity.
Can I apply for SEIS and EIS at the same time?
Yes. Most founders do. You'd raise your first £250,000 under SEIS, then continue under EIS in the same round, but the SEIS shares must be issued on an earlier day than the EIS shares. You cannot go the other way: once EIS shares are issued, you cannot go back and issue SEIS shares in the same company.
Can I apply for advance assurance without any investors lined up?
Technically yes, but it's harder. HMRC requires the names and addresses of at least one potential investor with every application. If you don't have any leads, you'll need to explain why and provide other evidence that the round is credible, which often means HMRC comes back with follow-up questions and timelines stretch.
Does SEIS/EIS advance assurance expire?
There is no fixed expiry date. Your assurance stays valid as long as the facts you submitted remain accurate. If your company's trade, structure, funding plan or share terms change materially, the assurance may no longer apply, and you may need to reapply.
What are the most common reasons HMRC rejects an advance assurance application?
The recurring reasons: incomplete documentation, no named potential investors, the company carrying on an excluded trade, share rights that fail the risk-to-capital test, vague or unrealistic financial projections, or language in the deck implying a pre-planned short-term exit. Most rejections can be fixed and resubmitted.
Does my company need to be based in the UK to qualify?
Your company does not need to be UK-incorporated, but it must have a permanent establishment in the UK to qualify for SEIS or EIS. Most founders applying will already have a UK Ltd company, which is the simplest route.
What happens after I receive advance assurance?
You share the HMRC letter with your investors, close your round, and issue the shares. Once you've spent at least 70% of the funds raised, you submit a compliance statement (SEIS1 or EIS1) to HMRC. They then issue SEIS3 or EIS3 certificates to your investors, which they use to claim their tax relief on their own self-assessment returns.