SEIS advance assurance: how to apply, documents and HMRC timings
How to apply for SEIS advance assurance: eligibility checks, documents, investor evidence, HMRC response targets and what happens after the letter.
By Steve Livingston FCA, founder of IP Tax Solutions
Technical sources checked: 21 September 2026
SEIS advance assurance is HMRC's indication, before shares are issued, that a proposed investment is likely to meet certain Seed Enterprise Investment Scheme conditions. It is based on the facts you disclose. It is optional and does not confirm that an individual investor qualifies for tax relief.
For a founder preparing a funding round, the practical task is to explain the proposed investment clearly, provide the supporting evidence and identify any difficult points before money and share documents are committed. HMRC's overview explains the scope of the service.
SEIS advance assurance at a glance
| Question | Answer |
|---|---|
| Is advance assurance compulsory? | No. It is a voluntary, non-statutory service. |
| When should I apply? | Before issuing the shares covered by the application, once you have a credible funding proposal. |
| How do I apply? | Through HMRC's online advance assurance service, yourself or through an authorised agent. |
| How long does HMRC take? | Its published aim is to respond to most applications within 15 working days and complex cases within 40 working days. A response is not necessarily an assurance. |
| Does it approve my investors? | No. Each investor's eligibility needs separate consideration. |
| Can investors claim relief using the assurance letter? | No. The company must complete the subsequent SEIS compliance process. |
Sources: HMRC application service, response targets and SEIS compliance guidance.
What does SEIS advance assurance cover?
Advance assurance concerns the proposed investment described in your application. It is not a permanent approval of the company or an endorsement of its prospects.
HMRC generally relies on the information supplied rather than auditing its accuracy. A letter obtained without full disclosure of relevant facts may provide no protection. If you acquired a business or intellectual property, have unusual share rights, or expect to change the proposed arrangements, explain that clearly. A difficult point left out of the application has not been cleared by HMRC. VCM60220.
Changes to the transaction, incomplete information and changes in the law or its interpretation can affect reliance on an assurance. Compare the final investment documents with the application before completion. VCM60240.
Check the company's SEIS position before applying
The following checks are a starting point, not the complete qualifying conditions:
| Check | What to establish |
|---|---|
| Gross assets | No more than £350,000 immediately before the relevant shares are issued, applying the group rules where relevant. |
| Employees | Fewer than 25 full-time equivalent employees at the share issue, including qualifying subsidiaries where the issuer is a parent company and applying the statutory counting rules. |
| Trading history | Whether the trade is a new qualifying trade. The three-year test concerns when the trade began, including under a previous owner, rather than simply the incorporation date. |
| Earlier investment | Previous SEIS funding and relevant aid affect the £250,000 headroom. Previous EIS or VCT investment can prevent SEIS qualification. |
Sources: ITA 2007 s.257DI, s.257DJ, s.257HF, s.257DL and s.257DK.
You must also assess the company's activities, independence, subsidiaries, use of money, share terms and risk-to-capital condition. Meeting the size limits alone does not make an investment eligible. See HMRC's company guidance.
What documents do you need for SEIS advance assurance?
Prepare a coherent application pack rather than a collection of unrelated attachments. The central documents are:
- Business plan and forecasts: what the company does, its growth plans and how it will spend the investment.
- Latest accounts, if available: consistent with the financial position explained in the application.
- Company and ownership documents: current memorandum and articles, proposed amendments and the register of members.
- Investment documents: the investor presentation and relevant shareholder agreements or other arrangements.
- Fundraising evidence: appropriate evidence of prospective investment for your route to market.
- Supporting explanations: including how the risk-to-capital condition is met and any eligibility issue requiring attention.
Use HMRC's current checklist and application page when assembling the submission. An agent also needs a signed authorisation letter dated within the preceding three months, included with each new application.
Your business plan should be the commercial plan provided, or intended to be provided, to investors. It should not tell HMRC a different story from the pitch deck. Explain how the money will be used and any expected follow-on funding. VCM60220.
Can you apply without investors already committed?
You do not need to have completed the investment. However, a company that has never raised investment under a qualifying venture capital scheme must demonstrate a credible intention and prospect of raising funds. HMRC does not offer a speculative company registration service.
For a direct raise, provide prospective investors' names, addresses and intended investment amounts. Naming someone expected to contribute a token part of a much larger round does not demonstrate serious expectations of raising the proposed amount.
Fund manager, promoter and crowdfunding routes have different evidence requirements. Evidence of substantive engagement matters; merely contacting a platform is insufficient. Companies that have previously raised under a qualifying venture capital scheme are not automatically rejected for omitting prospective investor details, although the funding source can still be relevant. VCM60230.
How to apply for SEIS advance assurance
1. Resolve the eligibility questions
The company must already be incorporated and have its Corporation Tax Unique Taxpayer Reference. VCM60210.
Identify the proposed share issue, funding amount, use of funds and relevant company history. Investigate any uncertainty rather than relying on a standard description of the business.
2. Reconcile the documents
Check that the forecast, pitch deck, share rights and application describe the same proposal. As a practical review, put them side by side and compare the funding amount, activities, ownership and investor terms.
3. Submit through HMRC's online service
Use the official application page. Keep a copy of the completed application and every attachment so you can check the eventual transaction against what was disclosed.
4. Answer any questions fully
An HMRC response may request more information. Address the question directly and explain any document changes. If the issue is structural, correcting the wording alone will not resolve it.
5. Check the final transaction before issuing shares
If the prospective investment or information supporting an issued assurance changes, HMRC's guidance requires a new application. Do not assume the earlier letter covers revised arrangements. VCM60270.
How long does SEIS advance assurance take?
HMRC's published response targets are 15 working days for most applications and 40 working days for complex cases. These are aims, not guaranteed completion times. The response may be a request for information or a refusal rather than an assurance. VCM60270.
For planning purposes, allow time before submission to review the structure and assemble the evidence, plus time afterwards for questions. Do not promise an investor a completion date solely by counting from HMRC's response target.
Why might HMRC refuse advance assurance?
An application can fail because HMRC cannot form a view or because the proposed arrangements do not meet the conditions. Those situations require different responses.
First establish whether the problem is missing evidence, a misunderstood fact or a substantive eligibility issue. For example, clarification may explain a business model, but it cannot change rights already written into investment documents.
There is no statutory right of appeal against an advance assurance refusal. That is distinct from the later statutory compliance process. Read HMRC's refusal guidance and overview.
For a practical example, our software university spin-out case explains an advance assurance refusal involving acquired software and the excluded activities rules. It illustrates why the underlying facts deserve attention before a standard application is submitted. Its outcome should not be treated as a prediction for another company.
What happens after advance assurance?
The assurance letter is not the investor's tax certificate. After issuing shares, the company must submit its SEIS1 compliance statement when the filing conditions are met. HMRC then considers whether to authorise the company to issue SEIS3 certificates to investors. HMRC's compliance guidance.
For SEIS1, at least one of these conditions must be satisfied:
- at least 70% of the money raised by that share issue has been spent on the qualifying business activity for which it was raised; or
- the relevant new qualifying trade has been carried on for at least four months by the issuing company or a qualifying 90% subsidiary.
The four-month limb concerns the trade, not simply four months since receiving the investment. These are SEIS conditions; do not assume the EIS filing rules are identical. ITA 2007 s.257ED.
Keep the application, final transaction documents, spending records and compliance submissions together. Our published SEIS compliance enquiry case explains why the work does not end when the assurance letter arrives.
What if you are raising SEIS and EIS together?
Plan the two investments together but test each scheme separately. No EIS or VCT investment may have been made in the issuing company, or a company that is its qualifying subsidiary at the SEIS issue date, on or before the SEIS share issue day. Issuing SEIS shares a few minutes before EIS shares on the same day does not solve that statutory restriction. ITA 2007 s.257DK.
EIS has its own conditions and limits. Some EIS limits changed from 6 April 2026, with different treatment for specified Northern Ireland companies. Do not use an old SEIS/EIS comparison table to approve a current funding round. See HMRC's current EIS investment guidance and the limits applying from 6 April 2026.
Do you need a specialist adviser?
You can apply directly. The value of specialist advice is identifying whether the proposed investment works and explaining the difficult points accurately.
A review is particularly useful where the company has acquired a trade or IP, has a group structure, proposes unusual investor rights, is arranging several funding stages, or has already received a refusal.
IP Tax Solutions advises founders, investors and professional advisers on complex SEIS and EIS matters. Steve Livingston is a UK chartered accountant who trained at KPMG, later became a partner at Crowe UK and founded IP Tax Solutions in 2013.
If you want help, discuss your SEIS or EIS position with us. Explain what the company does, the proposed raise, the intended share issue timing and the point causing concern. We can then agree the scope and fee for the work needed.
This guide provides general information. The company's facts, investment terms and each investor's position require separate consideration.
