A SAFE (Simple Agreement for Future Equity) is a way for early-stage start-ups to raise money quickly: an investor gives money now in return for the right to shares in the future, without fixing a valuation today. SAFEs are popular in the US and increasingly seen in the UK, but they come with important UK tax considerations. Here is a plain-English guide for England and Wales.
How a SAFE works
Under a SAFE, the investor pays the company a sum now, and in return gets a contractual right to receive shares later, when a defined event happens, typically:
- the company's next qualifying funding round (the SAFE converts into the shares issued in that round); or
- an exit (sale or listing); or
- sometimes a longstop date.
Crucially, a SAFE is not a loan: there is usually no interest and no maturity/repayment date. And it is not shares yet, it is a right to future equity.
Discounts and valuation caps
To reward the investor for backing the company early (and taking more risk), a SAFE usually converts on favourable terms:
- a discount, the investor converts at a percentage below the next round's share price; and/or
- a valuation cap, a maximum company valuation at which the investor's money converts, so they get more shares if the company's valuation has risen.
The investor typically converts at the more favourable of the discount or the cap.
The big UK issue: tax (SEIS/EIS)
This is where UK founders must be careful. The Seed Enterprise Investment Scheme (SEIS) and Enterprise Investment Scheme (EIS) give investors generous tax reliefs, a major reason UK angels invest. But those reliefs generally require shares to be issued at the time of investment. Because a SAFE issues shares later, a SAFE may not qualify for SEIS/EIS.
For this reason, UK start-ups often use an Advance Subscription Agreement (ASA) instead. An ASA may be capable of qualifying for SEIS/EIS if it meets HMRC's accepted conditions for advance subscription arrangements and all other statutory SEIS/EIS requirements (relating to the company, investor, shares and use of funds) are also satisfied. Broadly, the money should be a non-refundable advance subscription for shares, with no interest, and the shares issued within a short period. HMRC practice often points to around six months, but that is guidance/practice rather than a universal statutory deadline; the full SEIS/EIS conditions must be met.
So: if SEIS/EIS relief matters to your investors, a SAFE may be the wrong tool, take specialist tax advice and consider an ASA.
SAFE vs convertible loan note vs ASA
- SAFE, not a loan (no interest/maturity); a right to future equity; may not be SEIS/EIS friendly.
- Convertible loan note, debt (interest, maturity, creditor status) that converts to equity; also typically not SEIS/EIS friendly while it is debt.
- ASA, an advance subscription for shares that can be SEIS/EIS compatible if HMRC's conditions are met.
Pros and cons of SAFEs
Pros: fast and cheap; defers valuation; simple documentation; no interest or repayment date. Cons: tax (SEIS/EIS) risk in the UK; the investor has no shareholder rights until conversion; dilution and the discount/cap effect land later; less established under English law than ASAs/convertible notes.
Key takeaways
- A SAFE is money now for future shares (not a loan and not shares yet) usually converting at the next round, with a discount and/or valuation cap.
- The key UK concern is tax: SAFEs may not qualify for SEIS/EIS, which usually need shares issued at investment.
- UK start-ups often prefer an ASA, which may be structured to be SEIS/EIS-compatible if HMRC's conditions and all other SEIS/EIS statutory requirements are met (broadly: non-refundable, no interest, shares issued within a short period); take specialist tax advice.
- Choose between SAFE, convertible loan note and ASA based on tax and structuring, and take specialist advice.
Sources
- HMRC rules on the Seed Enterprise Investment Scheme (SEIS) and Enterprise Investment Scheme (EIS), and the Advance Subscription Agreement (ASA) as a SEIS/EIS-compatible structure
- Companies Act 2006 (allotment and issue of shares on conversion)
- General practice on SAFEs, convertible loan notes and ASAs in UK seed financings
--- This article is general information about the law of England & Wales as at 2026, not legal or tax advice. For advice on your circumstances, consult a qualified solicitor or tax adviser.