How to Apply for SEIS: The Four Steps
The SEIS application process from a founder who has run it: eligibility, advance assurance, the compliant raise, and the SEIS1 to SEIS3 paperwork.

In this article
The SEIS application is not one form; it is four gates in sequence, and founders who treat it as a single form end up redoing work mid-raise. The gates: prove to yourself you qualify, get HMRC comfortable in advance, run the raise so nothing disqualifies it, then file the paperwork that turns investor goodwill into certificates. Here is each gate, with timings and the traps.
SEIS application step 1: check you actually qualify
Before a single investor email, run the tests: trade under three years old measured from first sale, fewer than 25 full-time equivalents, gross assets under £350,000, headroom within the £250,000 lifetime cap after any counted grants, a trade off the excluded list, and genuine growth intent. The full list with the traps annotated is in the eligibility guide, and the five-minute checklist makes the first pass. Any ambiguous answer is worth a paid hour with an adviser now, when it is cheap.
Step 2: advance assurance
Assurance is optional in law and mandatory in practice: serious investors ask for the letter before serious conversations. You apply online with your plan, forecasts, articles, cap table, the raise amount and likely investors. Expect a few weeks; expect questions; do not treat the letter as permission to change the plan afterwards. The whole process, document pack to refusals, lives in the assurance guide.
Step 3: run the raise without disqualifying it
Most SEIS failures happen here, in the mechanics, not the merits. The commandments: cash subscriptions for new ordinary shares, no preferential protections; shares issued against cleared funds, dated and registered properly; no convertible loan notes, and advance subscription agreements only if properly drafted; tranches sequenced so the asset test passes before each issue; SEIS shares before any EIS shares; and family investors counted against the 30% connection line. The catalogue of ways rounds break is in where founders trip; read it as a pre-flight list.

Step 4: the paperwork that pays everyone
After completion, two conditions gate everything: four months of trading and 70% of the money spent on the qualifying activity. Only then can you file the compliance statement, SEIS1. HMRC reviews and returns your authorisation, SEIS2, with a unique reference, and you issue each investor their SEIS3 certificate, the document their relief depends on. File promptly, issue promptly; every idle week is an investor who cannot claim, and they remember. The investor-side view of this machinery is in how to claim.
The founder timeline, realistically
| Stage | Owner | Typical time |
|---|---|---|
| Eligibility check | You, plus an adviser hour | A week |
| Assurance application | You | A few weeks with HMRC |
| Raise and share issue | You and your lawyer | Deal-dependent |
| Trade and spend 70% | The business | 4+ months |
| SEIS1 to SEIS3 | You or your accountant | Weeks with HMRC |
The three application mistakes I keep seeing
- Starting assurance after opening the round. Investors move faster than HMRC; the stall lands at the worst moment.
- Treating the SEIS1 date as flexible. Four months and 70% are gates, and early filings bounce.
- Nobody owning the certificates. Assign SEIS3 issuance to a named person with a deadline, or it becomes everyone’s job and no one’s.
The document pack, gate by gate
Each gate has its paperwork, and assembling it early is most of the battle. For eligibility: incorporation documents, the first-invoice evidence behind your trade-age answer, a current FTE schedule, management accounts for the asset test, and your grant history. For assurance: the business plan and forecasts investors will actually see, articles, cap table, the raise terms and likely investors. For the raise: board minutes, resolutions, the share register and bank evidence of cleared funds preceding issue. For the compliance stage: the spend analysis proving 70%, and the trading evidence behind the four months. One folder, built once, serves all four gates and every investor data room after, as the assurance guide lays out.

If HMRC pushes back at the SEIS1 stage
Questions after filing are usually requests for evidence, the spend analysis, the trading dates, clarity on an instrument, and answer well, they resolve. A rejection is rarer and almost always traces to a gate skipped earlier: shares issued before funds cleared, a class right that offends the ordinary-share tests, the statement filed before the four months ran. The honest playbook: establish which condition failed, take advice before responding, and tell your investors the truth with a plan attached. Founders survive delayed certificates; what they do not survive is investors learning the problem from HMRC’s silence rather than the founder’s email.
Who does what: founder, lawyer, accountant
The application succeeds as a three-hander. The founder owns the story and the facts: the plan, the forecasts, the trade description, and the honesty of the eligibility answers. The lawyer owns the instruments: articles, share terms against the ordinary-share tests, board minutes, the register, and the sequencing of issues. The accountant owns the numbers and the filings: the asset test evidence, the spend analysis, the SEIS1 when its gates open, and the certificate logistics after. Rounds go wrong when one hand plays another’s part, founders drafting share terms from templates being the classic. The division costs a few thousand pounds across the raise; the mistakes it prevents cost investors their relief and founders their reputation.
Common questions
How do I apply for SEIS?
Four steps: confirm eligibility against the company tests, apply to HMRC for advance assurance, run a compliant raise of new ordinary shares for cash, then after four months of trading and 70% spend, file SEIS1 and issue SEIS3 certificates.
How long does an SEIS application take?
Assurance typically takes a few weeks. Certificates arrive months after the raise because of the four-month trading and 70% spending conditions.
Do I need advance assurance to raise under SEIS?
Legally no, practically yes: most investors will not commit without it.
What is form SEIS1?
The compliance statement a company files with HMRC after meeting the trading and spending conditions; it leads to SEIS2 authorisation and SEIS3 certificates.

Sources
gov.uk, Apply to use SEIS · HMRC Venture Capital Schemes Manual


