Your first business angel asks: "Are we signing a SAFE or a BSA Air?". You hesitate for three days, ask on Slack, and get five conflicting opinions. Short answer: if your startup is a French SAS and your angel is French, go with a BSA Air. It's the default instrument in 2026: a well-known legal framework, an 18% IR-PME tax reduction on conversion (subject to conditions), and French VCs and angels who are comfortable with the format. The SAFE is the right call when your entity is offshore (typically a Delaware C-corp) or when a US/UK investor refuses the BSA Air. A common hybrid: a SAFE for your American angel and a BSA Air for your French angel in the same round, with mirrored economic terms. This guide gives you the decision tree by scenario, an 8-criteria comparison, the tax nuance that steers French angels away from the SAFE, and the cases where neither one is the right answer. We're not lawyers: before you sign, talk to a startup lawyer.
The quick pitch: what each one is
SAFE (Simple Agreement for Future Equity) in 3 sentences
A convertible investment contract created in 2013 by Y Combinator. The investor puts money in today in exchange for the promise of shares at the next qualified round, at a favorable price (cap, discount, or both). It carries no debt, no interest, and no maturity date: it's simply a promise of future shares.
BSA Air (Bon de Souscription d'Actions, Accord d'Investissement Rapide) in 3 sentences
The French adaptation of the SAFE, launched the same year, 2013, by The Family and SB Avocats. Legally, it's a security (valeur mobilière) under the French Commercial Code: a warrant that entitles the holder to shares at the next round. Same economic logic as the SAFE, wrapped in a French legal structure.
For the BSA Air mechanics in detail
The full walkthrough (issuance, extraordinary general meeting, subscription form, conversion) is in the complete BSA Air guide. Here, we compare.
The quick comparison table
| Criterion | SAFE | BSA Air |
|---|---|---|
| Origin | Y Combinator (US, 2013) | The Family + SB Avocats (FR, 2013) |
| Legal nature | Sui generis contract, no formal classification under French law | Security under the French Commercial Code |
| Typical issuing entity | Delaware C-corp, LLC, sometimes an SAS through adaptation | SAS, SA, SCA (not SARL) |
| Conversion mechanism | Automatic at the qualified round | Warrant exercised at the qualified round, on a sale, or at a long-stop date |
| Floor / Cap / Discount | Standard cap, optional discount, no classic floor | Optional floor, cap optional but almost always included, 15-25% discount |
| Legal cost | Nearly free, YC template | Lawyer or platform (SeedLegals), French formalities to follow |
| Tax treatment (French investor) | No IR-PME, no PEA eligibility | 18% IR-PME on conversion if SME conditions are met, 30% flat tax on exit |
| French investor preference | Low | Common instrument for pre-seed and bridge rounds |
For a French startup, which one should you pick?
A decision tree with three branches. Two questions, in order:
Q1: Is your entity French (SAS, SA, SCA) or offshore (Delaware, Singapore, UK Ltd)? Q2: Are your investors mostly French, international, or a mix?
French entity + French investors: BSA Air by default
The most common case for an early-stage startup raising in France. An SAS, a French angel or French family office, and Paris-based VCs down the line. Go with the BSA Air without a second thought. It's what your lawyer will recommend, what SeedLegals will generate by default, and what your future Series A VC already knows.
French entity + US/UK investors: a mix is possible
You're an SAS, but an American angel joins the round, or a UK fund wants in. You have three options. You can offer a BSA Air and explain it (15 minutes of explaining, and their lawyer handles the translation). You can draw up a separate SAFE for them, giving you two contracts with aligned economic terms. Or you can turn down their check if you don't want the complexity. The clean approach: mirror documents, with the same cap and discount and a single coordinated conversion date.
Offshore entity + international investors: standard SAFE
You have a Delaware C-corp (through a flip or from day one) and you're raising from YC, US funds, or international angels. Use the YC post-money SAFE. It's the global standard, your Delaware lawyer knows it inside out, and nobody argues about the structure. A BSA Air makes no sense here.
Special cases: French team + US holding, planned Delaware flip
A French team with a US holding company means you're a US company paying salaries in France through a subsidiary. Your instrument follows the legal entity issuing the securities, not where the team is based. Same logic if you're planning a Delaware flip within 12 months: wait for the flip and raise on a SAFE directly, rather than setting up a BSA Air you'll have to restructure. On the European side, in March 2026 the Commission proposed EU Inc, a company status shared across all 27 member states that could make some Delaware flips unnecessary once adopted (EU Inc, the European startup status).
Taxes: the practical IR-PME difference
For a French angel, the difference comes down to taxes.
18% IR-PME: available with a BSA Air on conversion
Under the IR-PME scheme, a French investor gets an income tax reduction of 18% of the amounts paid for cash subscriptions to the share capital of an SME (Service Public, 2026). Since February 2026, the rate rises to 30% for JEIs (jeunes entreprises innovantes, or young innovative companies) and 25% for JEIIs (young innovative impact companies). For the BSA Air, the rule is subtle: subscribing to the warrant does not qualify for IR-PME (it isn't a subscription to share capital), but exercising the warrant on conversion does qualify if the SME conditions are met at the time of exercise. The eligible amount then covers both the nominal value and the share premium.
SAFE: typically not eligible for IR-PME
An American SAFE imported as-is creates two problems for IR-PME. It isn't a subscription to the share capital of a French SME (it's a contractual promise, not a French security). And if the issuing entity is offshore, even on conversion the French investor isn't subscribing to the capital of an SME in the French sense. Result: no IR-PME possible. For an angel investing €50,000, that means €9,000 to €15,000 less in tax reduction, depending on whether the company is a JEI.
The upshot: French angels often steer clear of the SAFE
On €50,000 invested in a French JEI:
- BSA Air converted into shares: a potential €15,000 reduction (30%).
- Equivalent US SAFE: zero.
Ask any French angel who's familiar with IR-PME: on equal economic terms, they'll prefer the BSA Air. The tax math alone explains it.
Safeguard: talk to a tax advisor
IR-PME comes with strict conditions on the company side (size, age, eligible activity, 5-year holding period) and on the investor side (tax residence, annual cap). Never promise IR-PME in a term sheet without sign-off from a tax advisor. The rules keep changing (the February 2026 changes on JEI/JEII), and the holding conditions can catch investors out at exit.
Investor preferences: who prefers what in 2026?
French VCs: BSA Air
Most Paris seed funds accept the BSA Air for their pre-seed and bridge tickets. It offers a known legal framework, clear tax treatment for French LPs, and standardized paperwork. A French VC proposing a SAFE on a French SAS in 2026 is sending an odd signal: either it's a special case (co-investing with a US fund) or they lack experience.
French business angels: BSA Air (often because of IR-PME)
For an angel investing in their own name, IR-PME is what makes the risk acceptable. So: BSA Air. Angels investing through a personal holding company (SC, SARL holding) care less about IR-PME but still favor the French framework.
US angels and VCs: SAFE
YC, Sequoia, a16z, and most American angels have worked with SAFEs since 2013. It's their default template, their lawyers know it, and the document runs 5 pages. Offering them a BSA Air means extra structuring work on their side. It's doable, with some friction. If your US angel is leading the round, offer them a SAFE.
International family offices: it depends
European family offices (Swiss, Luxembourg, German) are comfortable with both. They follow the round's lead. If a French VC leads, everyone signs a BSA Air. If a US fund leads, everyone signs a SAFE.
Is conversion into shares any different?
The mechanics are similar, the formalities differ.
SAFE: automatic conversion at the qualified round
At the closing of your qualified round (typically a Seed or Series A above a defined threshold), the SAFE automatically converts into preferred shares (or common shares, depending on the version). The calculation: amount invested divided by the conversion price (round price minus the discount, or the price at the cap, whichever is more favorable to the investor). There's no general meeting and no subscription form: the contract executes itself.
BSA Air: exercising the warrant, French-style formalities
When the trigger event occurs (qualified round, sale, or long-stop date), the investor exercises their BSA Air. They pay the exercise price (often a nominal €1), receive the shares, and get recorded in the share transfer register. On the company side, it's more formal: a decision by the president (under authority delegated by the extraordinary general meeting) recording the exercise, amendments to the articles of association if needed, and an update to the Kbis. The economic calculation is identical: the investor gets more shares than new investors for the same cash.
Practical differences for the founder
On equal economic terms, both produce a similar dilution effect. The cumulative effect of stacked post-money SAFEs, however, is trickier than with BSA Airs, and Y Combinator itself warns against stacking them. For how this plays out on your cap table, see BSA Air and your cap table: how to model the impact. For the terms to negotiate (discount, cap, floor), see how to negotiate discount, cap, and valuation on a BSA Air.
When to use neither
These instruments don't fit every situation.
If you're raising more than €2M: a direct equity round
Above €2M, a convertible no longer adds much. You set a valuation, negotiate preferred shares, and sign a full shareholders' agreement. It also sends a stronger market signal: a priced round shows you're ready for the structure. For the clauses to negotiate, see the French VC term sheet guide.
If you have 1-2 angels and a simple check: an equity SPA may be enough
Two French angels at €30,000 each, with a valuation agreed up front: a simple SPA (share purchase agreement) with a capital increase does the job. It's no more complex than a BSA Air, and your angels become shareholders immediately (with IR-PME applying directly at subscription). A BSA Air makes sense when you don't want to set the valuation yet. If you can set it, do.
FAQ
Can you sign a SAFE with a French SAS?
Technically yes, since the SAFE is just a contract. But with no formal classification under French law, it sits in a legal gray zone. In practice, if your lawyer wants to make the SAFE watertight in France, they'll effectively restructure it into a BSA Air. You might as well sign a BSA Air from the start.
Can a BSA Air convert across several rounds?
No, conversion happens once. At the triggering qualified round, all BSA Airs in the same tranche convert together according to their agreed terms. If you've issued several tranches at different times with different terms, each one converts under its own rules.
What's the legal cost of each instrument?
A SAFE costs almost nothing (YC template, signature). A BSA Air often costs a few thousand euros through a startup lawyer, or much less through a platform like SeedLegals. For a €200K round, a BSA Air typically represents 1 to 2% of the round. In return, it gives you a secure French legal framework that the SAFE lacks.
Which instrument is the fastest to sign in 2026?
Both can be signed within 1 to 2 weeks. The SAFE wins on contractual formalities (5 pages, no extraordinary general meeting). The BSA Air wins on familiarity with French investors (nothing to explain). With a French angel in a hurry, a BSA Air through SeedLegals can be signed in 5 days.
Pick your instrument based on your legal entity and where your investors are based. Two tools serve the same need through two distinct legal frameworks.
