Investing

EIS advance assurance and the EIS3 certificate

Advance assurance is HMRC's non-binding opinion before a raise. The EIS3 certificate, issued months afterwards, is the document that actually lets you claim.

By Craig Peterson20 September 20262 min readReviewed 20 September 2026

Two pieces of paper matter in an EIS round, and they do very different jobs. One reassures investors before they commit. The other is the only thing HMRC will accept when they claim.

This guide is one part of a set covering the whole scheme. The EIS hub lists every guide, from eligibility to claiming.

Advance assurance

Before the raise, the company can send HMRC its business plan, financial forecasts, latest accounts, articles, details of the proposed share issue and the names of prospective investors, and ask whether the issue is likely to qualify. HMRC replies with an opinion.

  • It is an opinion on the information supplied, not a ruling, and not binding if the facts turn out differently.
  • HMRC generally will not consider a speculative application with no identified prospective investors.
  • Turnaround varies and has often run to several weeks or longer.
  • It says nothing about the merits of the investment - only about the scheme conditions.

Most credible EIS rounds carry advance assurance, and its absence is worth asking about. But it is not a requirement for relief, and having it does not mean relief is safe: the company still has to behave correctly for three years afterwards.

EIS1, EIS2, EIS3

Sequence

From share issue to certificate

  1. 01

    Four months of trading

    The company must have carried on the qualifying trade for four months before it can apply. The clock starts at the later of the share issue and the start of trading.

  2. 02

    EIS1: the compliance statement

    The company tells HMRC about the share issue and confirms the conditions are met. It must be submitted within two years of the end of the tax year of the issue, or of the four-month period if later.

  3. 03

    EIS2: HMRC's authorisation

    HMRC reviews the statement and, if satisfied, issues an authorisation with a unique investment reference.

  4. 04

    EIS3: your certificate

    The company completes a certificate for each investor showing the company details, the amount subscribed, the date of issue and HMRC's reference.

What to check on the EIS3

  • Your name and address, exactly as HMRC holds them.
  • The amount subscribed and the number of shares.
  • The date of issue - this sets the three-year clock and the tax year of the claim.
  • HMRC's unique investment reference, which you will need for the claim.

Keep the certificate. HMRC can ask for it, and a replacement depends on the company still existing and being willing to issue one. Once it arrives, follow how to claim EIS relief. The SEIS equivalents are covered in advance assurance and the SEIS3 certificate.

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Written by

Craig Peterson

Co-Founder and Chief Operating Officer, GCV Labs

Craig Peterson is Co-Founder and Chief Operating Officer of GCV Labs, where he has helped create, launch and scale technology-enabled ventures including Intelligence Fusion, n-gage.io, Business Finance Market, Valius Global and Quva.

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