Advanced Subscription Agreements and SEIS: What Founders Sign

An advanced subscription agreement is the standard way a young UK company takes investment money before a priced round without breaking SEIS. The investor pays now, the shares arrive later at a discount to the next round’s price, and, if the agreement is drafted to HMRC’s conditions, the relief survives. Drafted casually, the same document quietly destroys it. This guide covers what an advanced subscription agreement is, the conditions HMRC expects, and the mistakes that turn early money into a relief-killing loan.

What an advanced subscription agreement is

An advanced subscription agreement (ASA) is a contract in which an investor pays a subscription now for shares to be issued at a future point, usually the next funding round, usually at a discount of 10% to 30% to that round’s price. It exists because early companies often need money before they can sensibly price themselves, and because the obvious alternatives, loans and convertible notes, are debt, and SEIS money can never start life as debt.

That last sentence is the whole reason ASAs matter. SEIS relief attaches to ordinary shares subscribed in cash. A convertible loan note carries interest, a repayment right and creditor status; money that arrives that way is not a share subscription, and converting it later does not repair the history. The ASA is the instrument the market built to take early cash while staying on the equity side of that line.

The conditions that keep an ASA SEIS-compatible

HMRC’s published position is that an advance subscription can work for SEIS and EIS only where the agreement is equity-like in substance from the first pound. In practice that means the document should have all of the following features:

No refund in any circumstances. The investor cannot get the money back. If the company never raises the next round, the shares still get issued at the longstop; the cash never returns as cash. Any refund right, however remote, makes the arrangement look like a loan.

No interest. The money earns nothing while it waits. Interest is what debt pays; an ASA that accrues it has already lost the argument.

A short longstop. The agreement must convert into shares within a fixed, short period even if no round happens. HMRC’s guidance treats six months as the acceptable outer limit. Longer backstops, or agreements with no backstop at all, fail.

No investor protections that look like security. No charge over assets, no creditor ranking, no ability to assign the agreement to someone else. The investor is standing in the queue for shares, nothing stronger.

Meet all four and the money can qualify when the shares are issued. Miss one and the entire tranche, and everyone in it, is exposed.

When the SEIS clock actually starts

Here is the subtlety founders miss: relief attaches to the share issue, not the payment. The three-year holding period, the eligibility tests, and the relief itself are all measured at the date the shares are issued under the ASA, which might be months after the money arrived. Two consequences follow.

First, the company must still qualify at issue. If the ASA money is taken while the trade is two years and ten months old, but conversion happens after the third birthday, the SEIS window has closed and the shares cannot qualify. Count forward from the longstop, not from today.

Second, the investor’s relief lands in the tax year of issue (with the usual one-year carry back available from there). An investor planning relief against a particular year’s bill needs to know the conversion date, not the payment date. The mechanics of timing a claim are in how to claim SEIS tax relief and the carry back guide.

The mistakes that actually happen

The same handful of failures repeat across rounds. A template convertible loan note is downloaded and relabelled as an ASA, with the interest clause left in. A well-meaning founder promises a nervous investor their money back if the round falls through, in an email that becomes part of the record. The longstop is set at twelve months because it felt generous, and HMRC declines assurance.

The valuation cap and discount are drafted so aggressively that the eventual share price looks like a pre-agreed sweetheart deal rather than a market subscription. Or the ASA converts on time, but nobody issues the shares in Companies House filings and the register for another quarter, leaving the paper trail incoherent. The wider family of round-breaking errors lives in common mistakes that break SEIS status.

Using an ASA properly: the short process

Mention the ASA in your advance assurance application, and attach the draft; HMRC will consider the instrument as part of the application, which is exactly what you want. Take the money only after the document is signed with the four conditions intact. Diarise the longstop. At conversion, issue the shares promptly, file, update the register, and then start the SEIS1 process once the trading or spend gate is met, as with any round. The full sequencing is in structuring the round, and the assurance paperwork in the advance assurance guide.

Sources

HMRC Venture Capital Schemes Manual (advance subscription agreements); HMRC, Apply to use the Seed Enterprise Investment Scheme. Figures and conditions correct as at 17 July 2026, checked against our rules and limits reference. Education, not legal advice: have any ASA drafted or reviewed professionally.