What HMRC actually needs, why applications get rejected, and how to apply — written for founders raising their first round.
SEIS advance assurance is HMRC’s written opinion, given before you issue shares, that a proposed share issue is likely to qualify under the Seed Enterprise Investment Scheme. It is not a guarantee, not legally binding, and carries no right of appeal — but most angel investors expect to see it before they commit money, so in practice it gates your round.
You are not legally required to get it. HMRC is explicit that there is no requirement to obtain advance assurance before issuing shares. Founders get it anyway because it converts an abstract promise (“you’ll get 50% income tax relief”) into something an investor can see in writing from HMRC.
HMRC looks at your proposed share issue in advance and tells you whether, on the information you gave, it would be able to authorise SEIS certificates for your investors once the shares are actually issued.
Most rejected applications fail here rather than on the technical SEIS conditions. HMRC’s advance assurance service is discretionary and non-statutory, and it is deliberately not a registration service.
Your company must already be incorporated at Companies House and have received a Unique Taxpayer Reference from HMRC. You cannot apply for advance assurance for a company you intend to form. The UTR arrives by post after incorporation, typically within a couple of weeks — if you are planning a raise, incorporate early enough that this is not the thing holding you up.
This is the single most common reason a first-time application is rejected. HMRC will not process speculative applications from companies that have never raised under a venture capital scheme. You must supply the name and address of each prospective investor and the amount each intends to invest.
HMRC is specific that it is not enough to name one or two investors who between them account for a small slice of the round. You have to show a serious expectation that named individuals will invest the amount stated in the application. Naming a friend who might put in £2,000 against a £150,000 target will not do it.
If a platform, fund manager or promoter is involved and you do not disclose it, any assurance HMRC gives is invalid. Non-disclosure does not just risk the application — it voids the answer.
SEIS is deliberately narrow. It is aimed at companies at the very beginning. These figures are unchanged for 2026/27.
| Condition | SEIS requirement (2026/27) |
|---|---|
| Trading age | Under 3 years |
| Gross assets before the share issue | Not more than £350,000 |
| Employees | Fewer than 25 full-time equivalents |
| Company lifetime SEIS limit | £250,000 |
| Investor income tax relief | 50% of the amount invested |
| Investor annual limit | £200,000 per tax year |
| Establishment | UK permanent establishment |
| Shares | New, fully paid ordinary shares, subscribed for in cash |
| Prior venture capital funding | No previous EIS or VCT investment before the SEIS shares |
Beyond the mechanical tests sits a judgement call. HMRC applies a risk-to-capital condition: the company must be seeking to grow and develop over the long term, and the investment must carry genuine risk of loss of capital greater than the net return. Structures that look engineered to deliver tax relief with the risk stripped out fail this, however well they satisfy the arithmetic. Your application has to state that you meet it.
Some trades cannot use SEIS at all, including dealing in land or shares, banking and financial services, legal and accountancy services, property development, farming, running hotels or nursing homes, and generating most forms of energy. If a meaningful part of your trade sits in an excluded category, address it in the application rather than hoping it is not noticed.
HMRC gives an assurance only on the basis of what you provided, and does not generally check the accuracy or completeness of what you send. That cuts both ways: a thin application gets a thin answer, and an inaccurate one produces an assurance that will not hold.
HMRC asks companies to give full and open information and to flag areas of doubt. Founders instinctively do the opposite — they smooth over the awkward bit. Naming a borderline issue and explaining your position usually resolves faster than leaving HMRC to find it and come back with questions.
By submitting the form you are also confirming that the company will be able to complete the statutory declaration on the SEIS1 compliance statement when the shares are eventually issued. That is a forward-looking undertaking about how the company will behave, not just a description of where it is today.
For a fuller treatment of each step, including the investor schedule and how to write the trade description, see how to apply for SEIS advance assurance. To work through it item by item, use the free SEIS advance assurance checklist.
HMRC typically responds in around four to six weeks, and the timetable is entirely HMRC’s. No adviser controls it. Apply at least eight weeks before your target close so a single round of follow-up questions does not push you past it. Busy periods around the end of the tax year run longer. For the full stage-by-stage timeline and what causes delays, see how long SEIS advance assurance takes.
We prepare and submit your application on a two-working-day turnaround from receiving complete information. The decision timetable belongs to HMRC. Any adviser promising a guaranteed clearance turnaround is promising something that is not theirs to give.
An advance assurance does not carry a formal expiry date, but it is given on the facts you presented. If the round changes materially — a different amount, a different share class, a different trade, a much later issue date, or different investors — the assurance may no longer describe what you are actually doing, and you should go back to HMRC rather than rely on it.
Founders routinely overstate this in pitch decks. Being precise about it is a credibility signal to a sophisticated angel.
Advance assurance gets the money in. The compliance step is what actually delivers the relief your investors were promised, and it is where the real deadline sits.
Two years feels comfortable until the company is eighteen months into building a product and nobody remembers the form exists. This is the most expensive administrative deadline a seed-stage founder can miss — and the cost lands on your investors, not you.
You can apply for advance assurance covering both schemes, and many companies do. The sequencing rule matters: where SEIS and EIS shares are issued in the same accounting period, the SEIS shares must be issued first. Getting this backwards can cost the SEIS relief entirely.
In practice most founders exhaust the £250,000 SEIS lifetime allowance before moving to EIS, because 50% relief is a far stronger hook for an angel than 30%. EIS then covers the larger cheques — and from 6 April 2026 the EIS company limits rose sharply, so more companies stay eligible for longer. See EIS advance assurance for the seven-year rule and knowledge-intensive route, and SEIS and EIS tax relief for startups for the full comparison.
| What happens | Underlying cause |
|---|---|
| Rejected as speculative | No named prospective investors, or named investors covering only a token share of the round |
| Returned before assessment | Company not yet incorporated, or no UTR issued |
| Extended questioning | Trade sits close to an excluded activity and the application does not address it |
| Risk-to-capital challenge | Structure reads as designed around the relief rather than around growth |
| Assurance later invalid | An intermediary, prior funding or group structure was not disclosed |
| Round closes without it | Applied four weeks before target close instead of eight |
We prepare and submit SEIS advance assurance applications for UK founders, and we handle the compliance step that follows so the relief actually reaches your investors.
Engagements are led by Godwin Pinto ACA (ICAI), former PwC and a member of ICPA. See also our fundraising support service, the SEIS & EIS tax relief calculator, our R&D tax relief work, and startup accountants more broadly.
No. There is no legal requirement to obtain advance assurance before issuing shares. It is optional, discretionary on HMRC’s side, and non-statutory. Most angel investors expect to see it before committing, so in practice it functions as a gate on the round even though it is not required by law.
HMRC typically responds in around four to six weeks, and the timetable is HMRC’s alone. Apply at least eight weeks before your target close so that one round of follow-up questions does not derail it. AccTek prepares and submits the application on a two-working-day turnaround from receiving complete information; the decision timetable belongs to HMRC.
No, if your company has never raised under SEIS, EIS, VCT or SITR. HMRC does not accept speculative applications and requires the names, addresses and intended investment amounts of prospective investors. Naming one or two investors covering only a small share of the target round is not sufficient — you must show a serious expectation that named individuals will invest the stated amounts.
No. Advance assurance is HMRC’s opinion on the proposed share issue, given on the information supplied, and is not an assurance of relief for any particular investor. Investors must meet their own conditions, including not being connected with the company, holding no more than 30% of shares or votes, having sufficient income tax liability, and holding the shares for at least three years.
There is no formal expiry date, but the assurance is given on the facts presented. If the raise changes materially — a different amount, share class, trade, investor group or a much later issue date — the assurance may no longer cover what you are doing, and you should return to HMRC rather than rely on it.
Yes. A single application can cover both schemes. Where SEIS and EIS shares are issued in the same accounting period, the SEIS shares must be issued first. Most founders exhaust the £250,000 SEIS lifetime allowance before moving to EIS.
The SEIS1 compliance statement must be filed within two years of the end of the tax year in which the shares were issued. Miss it and your investors can permanently lose their income tax relief. Diarise it on the day shares are issued. You cannot file until the company has traded for four months or spent at least 70% of the SEIS money raised.
No, a company can apply itself. Founders typically use an adviser because the application turns on judgement calls rather than form-filling — how the trade is described against the excluded-activities list, how the risk-to-capital condition is evidenced, and how the investor schedule is presented. Where an agent applies on your behalf, HMRC requires a signed letter of authorisation from the company.
We’ll tell you honestly whether you’re ready to apply — before you spend eight weeks finding out.
General information for UK founders based on SEIS rules for the 2026/27 tax year and HMRC’s published guidance, current at the date of writing. Advance assurance is discretionary and non-statutory, and tax reliefs depend on individual circumstances. This page is not tax advice — speak to an accountant about your specific position.
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.
