Seed Funding UK: Legal Guide for Startup Founders

Overview

Seed funding is the earliest meaningful round of external investment a company takes on. It typically follows friends and family money or founder savings, and it comes in before a Series A. In the UK, seed rounds are often in the region of a few hundred thousand pounds, though this varies widely depending on the sector and the founder's network.

The money usually comes from angel investors, seed funds, accelerators, or a mix of all three. Legally, a seed round is a transaction in which the company issues new shares, convertible instruments, or takes on debt in exchange for cash.

It is governed by a patchwork of rules including the Companies Act 2006, the Financial Services and Markets Act 2000, and the tax legislation underpinning SEIS and EIS reliefs. The paperwork varies depending on the structure you choose, but the core idea is the same: money in, rights out. Getting the rights side correct matters, because those rights travel with the company for years.

Key steps

1. Get your cap table and company records straight. Before you speak to investors, make sure your Companies House filings are current, your statutory registers are accurate, and your cap table reflects reality. Any prior share issues, option grants, or informal promises to early contributors should be documented. Investors will check this during due diligence, and surprises at this stage can kill a deal or force you to renegotiate on worse terms.
2. Decide on the funding structure. The most common options at seed stage are priced equity rounds, convertible loan notes, and Advanced Subscription Agreements. Each has different implications for valuation, dilution, tax relief eligibility, and how quickly you can close. An ASA or convertible can be faster and avoids setting a valuation today, but a priced round gives certainty. Think about what suits your stage and your investors.
3. Check SEIS and EIS eligibility early. Many UK angels expect SEIS or EIS relief to be available, because it substantially reduces their downside. The rules are strict, covering the company's age, trade, gross assets, and employee count, and certain share rights can disqualify you. Applying for advance assurance from HMRC before the round can make your company far more attractive to investors.
4. Negotiate the term sheet carefully. The term sheet is usually non-binding but it sets the commercial framework everything else flows from. Pay particular attention to valuation, liquidation preferences, anti-dilution protection, board composition, consent rights, pre-emption, drag and tag along provisions, and founder vesting. Once something is agreed in the term sheet, it is very hard to walk back in the long-form documents.
5. Complete due diligence and sign the long-form documents. Investors will want to see contracts, IP assignments, employment agreements, any regulatory permissions, and your financials. The main documents at closing are typically a Subscription Agreement and a Shareholders' Agreement, alongside amended Articles of Association. Read them carefully, and make sure what has been signed matches what was agreed at term sheet stage.

Common questions