Investor Readiness Guide

SEIS and EIS Explained for UK Founders

The two tax schemes that make UK angel investing actually work, plus how to get advance assurance before you start raising.

Who should read this: UK founders preparing to raise from angels or syndicates, anyone planning a pre-seed or seed round, and any founder whose investors are asking about SEIS or EIS eligibility before they'll commit.

Updated May 2026 · 9 min read

If you're raising money from individual investors in the UK, SEIS and EIS are the most important acronyms you'll learn. They're government schemes that give your investors serious tax relief when they back your company. Most UK angels won't write a cheque without SEIS or EIS eligibility. The relief reduces their downside risk by up to half, and that's the whole reason the schemes exist.

Here's everything you need to know, including a step-by-step on getting HMRC advance assurance before you start pitching.

SEIS vs EIS at a glance

Most founders use both schemes at different stages. SEIS comes first for very early-stage companies, EIS comes next as you grow.

SEISEIS
Stage it suitsPre-seed, first £250k of investmentSeed and beyond
Investor income tax relief50%30%
Investor annual cap£200,000 per tax year£1m per tax year (£2m if at least £1m goes into knowledge-intensive companies)
Company lifetime raise£250,000£24m (most companies), £40m (knowledge-intensive)
Company annual raisen/a (one-off lifetime cap)£10m (most), £20m (knowledge-intensive)
Company age limitLess than 3 years from start of tradeLess than 7 years from first commercial sale (10 for knowledge-intensive)
Employee limitFewer than 25Fewer than 250 (500 for knowledge-intensive)
Gross assets cap£350,000 at share issue£15m before share issue, £16m after (higher for knowledge-intensive)
CGT exemption on exitYes, after 3 years heldYes, after 3 years held
Loss relief if it failsYes, against income or CGTYes, against income or CGT
Sunset clauseNone6 April 2035 (extended in Finance Act 2024)

The EIS company limits were raised in 2026 from £5m annual and £12m lifetime. Older articles still quote the previous numbers, so double-check anything you read elsewhere against gov.uk.

SEIS in plain English

SEIS is the early-stage scheme. It exists to make backing brand-new companies palatable for angels who are taking on real risk. 50% income tax relief is the closest thing to a money-back guarantee in early-stage investing.

Two practical points the table doesn't capture:

EIS in plain English

EIS is the bigger sibling. It works on the same principle but for companies that have outgrown SEIS, with smaller relief (30%) but much larger raise limits.

Two things worth highlighting beyond the table:

SEIS first, then EIS

Most UK startups use both schemes in sequence, not in parallel. The natural progression looks like this. You launch the company. You raise your first £250,000 from angels under SEIS, giving them the maximum 50% relief. You hit the SEIS lifetime cap. You move to EIS for the next round, giving new investors 30% relief instead of 50% but unlocking a much bigger funding pool.

A few practical points:

Worked example: what £20,000 of SEIS looks like for an investor

This is the calculation that makes angels say yes.

An angel invests £20,000 in your SEIS-qualifying startup.

Worst-case downside: roughly 28% of the cheque. Best-case upside: unlimited and tax-free. That asymmetry is the whole game. The same logic applies to EIS at 30% relief instead of 50%.

Important caveats on these numbers

This is a stylised illustration, not a guarantee. The maths assumes:

Before quoting these numbers to investors, run the specific scenario past an accountant or tax adviser. Investors will ask, and getting it slightly wrong erodes trust faster than not having a worked example at all.

Why advance assurance matters more than the schemes themselves

Advance assurance is a letter from HMRC saying your company is likely to qualify for SEIS or EIS. It's free to apply for. You don't legally need it. But practically, it's the single most useful piece of paperwork in a UK seed round.

Investors will ask for it on the first call. Without it, you're asking them to take their word that they'll get the tax relief. With it, they don't have to. That changes the conversation.

Advance assurance equals investor confidence. Walking into a pitch with the letter in hand tells angels they don't need to take the eligibility on faith. Walking in without it tells them you're either disorganised or gambling with their relief. Get it before your first scheduled meeting. Not after. Not during. Before.

Step-by-step: how to get HMRC advance assurance

Step 1. Confirm you qualify

Read HMRC's eligibility rules end to end. The most common reasons for rejection:

If anything is borderline, get specialist tax advice before applying. HMRC removed the right of appeal on advance assurance decisions, so a rejection is final for that application.

Step 2. Pull together your documents

Send HMRC this exact bundle:

DocumentWhat it should show
Business plan or pitch deckWhat the company does, who it serves, how it makes money, how the funds will grow it
Three-year financial projectionsRevenue, costs, headcount, cash flow
Latest company accounts (and any subsidiaries)Filed accounts if you have them, management accounts if you don't
Memorandum and Articles of AssociationUp-to-date, as filed at Companies House
Share registerCurrent shareholders and shareholdings
Funds raised summaryHow much you're raising, how it will be used
Any draft subscription or shareholder agreementIf applicable

A clean pitch deck does most of this work. Treat the business plan as a structured Q&A answering exactly what HMRC asks rather than a separate document.

Step 3. Get evidence of investor interest

Show HMRC this is a real fundraise, not a hypothetical one. Acceptable evidence:

You don't need a fully closed round. You do need names.

Step 4. Write a risk-to-capital statement

A short narrative, two paragraphs is usually enough. Cover two things:

Don't paste in template wording. HMRC reads these.

Step 5. Submit through the gov.uk portal

Use the venture capital schemes service on gov.uk. Attach the documents above plus the relevant SEIS or EIS checklist (HMRC publishes both). If you're applying for both schemes, submit one combined application.

Step 6. Wait 4 to 8 weeks

HMRC's published target is 15 to 40 working days. Most applications take six to eight weeks in practice. They may come back with questions. Reply quickly. Each round of questions effectively pauses the clock.

Step 7. Forward the assurance letter to investors

If HMRC is satisfied, you receive a letter confirming the company is likely to qualify. That letter is what you forward to investors. Keep a clean PDF copy ready to share before any pitch meeting.

Common mistakes founders make

Applying too late. Founders often start the application the same week they start pitching. By the time the letter arrives, the round is dead. Apply six to eight weeks before your first scheduled investor meeting at the absolute latest.

Assuming you qualify without checking. Some activities are excluded outright, others are partially excluded. Read HMRC's list. If you're a fintech, prop-tech, or anything close to financial services, get advice before assuming.

Confusing SEIS and EIS. They're separate schemes with separate caps. A company can use SEIS first then move to EIS once it outgrows the SEIS limits. Investors can use both for the same company in the same round. Get the structure right with a tax adviser.

Missing the risk-to-capital statement. This is now the single most common reason for rejection. HMRC takes it seriously. Don't paste in vague text from a template.

Breaking the rules after the investment. SEIS and EIS eligibility is conditional for at least three years after each share issue. If you change trade significantly, return capital to investors, or breach the employee or asset limits, you and your investors lose the relief. Always check before making major structural changes.

Forgetting the investor side. SEIS and EIS relief is claimed by the investor, not the company. After share issue, you have to send each investor a compliance certificate (SEIS3 or EIS3) so they can actually claim. Founders sometimes forget this step. Investors don't.

Timeline at a glance

A realistic SEIS or EIS timeline from "I'm planning to raise" to "round closed":

What good looks like

A founder who has SEIS or EIS advance assurance in hand before their first scheduled investor meeting, can explain the scheme in two sentences, has structured the company to qualify from day one, and treats compliance certificates as part of their post-close checklist rather than an afterthought. The best founders treat this paperwork as part of their fundraising prep, not a tax-adviser problem to deal with later.

What to read next

SEIS and EIS sit alongside the rest of your seed-round paperwork. Once advance assurance is in hand, the next pieces are usually:

If grants are a better fit at your stage (non-dilutive, no investor management overhead), try YourGrantBuddy.com.

Where to go deeper

Ready to find funding?

Answer five questions and see the investors, grants, and funding sources that fit your stage and sector.

Try the funding finder →

Missing something? Tell us. We're building this in the open and we want to get it right.

This is general information, not financial, tax, or legal advice. SEIS and EIS rules are complex and change. Always check the latest HMRC guidance and seek independent professional advice before making any tax or investment decisions.

Common Questions

Get the full Start playbook emailed to you.
Free. One email. Everything for founders at your stage.