BSA Air: The Complete Guide for Startups [2026]

You have an investor ready to put €100,000 into your startup. They want to sign this week. The problem: your company has no valuation, you don't have a lawyer on hand, and a traditional fundraise would take three months. This is exactly the scenario the BSA Air was built for. The BSA Air (Bon de Souscription d'Actions, Accord d'Investissement Rapide, or "share subscription warrant, fast investment agreement") lets a startup raise funds in a matter of days without setting a valuation. The investor transfers the money immediately and receives warrants that convert into shares at the next financing round, with a discount of 15 to 25%. It's the standard tool for bridge and pre-seed rounds in France. This guide walks through the full mechanism, the terms to negotiate (discount, cap, floor), and how to set up a BSA Air in practice, from a founder's point of view.

What is a BSA Air?

The BSA Air is a financial instrument created in 2013 by the law firm SB Avocats and the investment company The Family, specifically for the French startup ecosystem. The goal: to reproduce, under French law, the speed and simplicity of the American SAFE (Simple Agreement for Future Equity), invented by Y Combinator.

The principle is simple. An investor brings funds to a startup. In exchange, they don't receive shares (which would require a valuation) but share subscription warrants. These warrants convert automatically into shares at a future trigger event (typically the next fundraise). The BSA Air investor gets a discount on the share price, as a reward for taking on early risk.

Legally, the BSA Air is a transferable security under the French Commercial Code, issued by decision of the extraordinary general meeting (or by the president under a delegation of authority). It's a private agreement between the company and the investor.

A simple definition of the BSA Air (Accord d'Investissement Rapide)

BSA Air = "I give you money now, you give me shares later, at a favorable price."

More precisely:

• The investor pays in a sum (the "subscription amount") immediately.
• They receive BSA Airs, which are rights to receive shares in the future.
• At the trigger event (a qualified round, an acquisition, or a deadline), the BSA Airs convert automatically into shares.
• The conversion price is calculated with a discount relative to the price paid by the investors in the following round.

The BSA Air does not grant shareholder status until conversion has happened. The BSA Air investor has no voting rights, no dividend rights, and no access to general meetings. They hold a future economic right, and nothing more.

BSA Air vs SAFE: the French equivalent

The BSA Air is often described as "the French SAFE." The comparison is useful, but the two instruments differ on several important points:

The key point for founders raising internationally: if your investors are American, they know the SAFE but not the BSA Air. Two options: use a SAFE if your legal structure allows it (a US holding company), or explain the BSA Air as its French equivalent. The economic terms are the same; it's the legal wrapper that changes. For a detailed point-by-point comparison, see our BSA Air vs SAFE comparison.

BSA vs BSA Air vs BSPCE: what's the difference?

Three instruments, three uses. The confusion is common.

BSA (Bon de Souscription d'Actions): a warrant that gives the right to buy shares at a price set in advance. Used to attract advisors or strategic partners. The buyer pays for the BSA, then exercises the right later. The valuation is fixed at the time of issuance.

BSA Air (Accord d'Investissement Rapide): a subscription warrant whose conversion price is not fixed at issuance but is determined at the trigger event (a qualified round). That's the "Air": the price "floats" until conversion. Used to raise funds quickly without a valuation.

BSPCE (Bons de Souscription de Parts de Créateur d'Entreprise): an incentive instrument for employees and executives. The recipient can subscribe for shares at a preferential price. Favorable tax regime (30% flat tax instead of income tax on salary). Used to attract and retain talent, not to raise funds.

How a BSA Air works: the mechanism step by step

The BSA Air follows a three-phase lifecycle: issuance, holding, and conversion. Each phase has its own rules.

Issuance and subscription

Phase 1: The company issues the BSA Airs.

The extraordinary general meeting (EGM) authorizes the issuance of the BSA Airs, or the president uses an existing delegation. The president's report sets out the terms of issuance: the number of BSA Airs, the subscription amount, the discount rate, the trigger events, and the deadline.

Phase 2: The investor subscribes.

The investor signs the subscription form and pays in the funds. In exchange, they receive the BSA Airs. The contract is a 5- to 15-page document (versus 50 to 100 pages for a shareholders' agreement in a traditional round).

Typical timeline: 1 to 3 weeks between first contact and the wire transfer. That speed is what makes the BSA Air attractive.

Formalities:

• Drafting the president's report or EGM minutes
• Subscription form signed by the investor
• Wire transfer of the funds
• Entry in the share transfer register

The BSA Air was designed to be simple. A specialist lawyer can draft the documents in 48 hours. Online platforms like SeedLegals automate the process: configuration, document generation, and signature collection all in one interface.

Trigger events (round, acquisition, liquidation)

The BSA Airs convert automatically when a trigger event occurs. The three classic cases:

1. The qualified round (the main case). The startup completes a fundraise that exceeds a minimum threshold (defined in the contract, typically €500K to €1M). The BSA Airs convert into shares at the round price, less the discount. This is the ideal scenario: everyone is happy.

2. The acquisition. If the startup is bought before completing a qualified round, the BSA Airs convert according to the terms set in the contract (often based on the acquisition valuation, less the discount). The BSA Air investor takes part in the exit.

3. The deadline (forced conversion). If no trigger event occurs before a set deadline (typically 18 to 36 months), the BSA Airs convert automatically based on a floor valuation (the "floor") or a negotiated valuation. This is the safety net for the investor.

4. Liquidation. In the event of winding up the company, the BSA Air investor is repaid their initial contribution (if any assets remain) before the founders recover anything. The order of priority depends on the terms of the contract.

Converting into shares: how it actually works

On conversion day, here's what happens:

1. The trigger event occurs (the startup announces a €2M round at an €8M pre-money valuation).
2. The price per share of the new round is calculated (valuation / number of shares = price per share).
3. The BSA Air conversion price is calculated: round price per share × (1 − discount rate). If the discount is 20% and the price per share is €100, the BSA Air conversion price is €80.
4. The number of shares allotted to the BSA Air investor is calculated: amount invested / conversion price. If the investor put in €100,000 and the conversion price is €80, they receive 1,250 shares (instead of 1,000 at the round price).
5. The BSA Airs are cancelled, the shares are issued, and the investor joins the cap table.

The BSA Air investor therefore receives more shares than the investors in the following round for the same amount invested. That's the reward for taking on early risk.

Discount, cap, and floor: the key terms to negotiate

Three terms determine the economic outcome of a BSA Air. Negotiated poorly, they can cost the founder dearly or put off the investor. For 2026 market benchmarks and negotiation scripts, see the dedicated guide: negotiating the discount, cap, and valuation.

How to set the discount (15-25% standard)

The discount is the percentage reduction the BSA Air investor gets on the share price at conversion. It's the compensation for risk.

Standard range: 15 to 25%.

• 15%: an institutional investor, a startup with strong traction, a qualified round expected within 6 months.
• 20%: the most common case, a balanced compromise between investor risk and founder dilution.
• 25%: a very early-stage startup, high risk, a long conversion horizon (18+ months).

Above 25%, ask yourself: is the investor taking on too much risk? Or is your startup not ready to raise?

Valuation cap and floor

The cap (valuation ceiling) protects the investor. If the valuation at the next round soars, conversion happens based on the cap, not on the actual valuation. The investor thus gets a lower price per share (and therefore more shares).

Example: Cap of €3M. If the next round happens at a €10M valuation, the BSA Air investor converts based on €3M (not €10M). They receive many more shares. Without a cap, they would have converted on €10M with just the discount.

The floor (valuation floor) protects the founder. If the valuation at the next round is very low (a downround), conversion happens based on the floor, not the actual valuation. The founder limits the dilution.

Example: Floor of €1.5M. If the next round happens at an €800K valuation, the BSA Air investor converts based on €1.5M. The founder is diluted less than if conversion happened on €800K.

Practical advice:

• The cap is almost always present. Without a cap, the investor has little upside protection, and that can block the negotiation.
• The floor is rarer but useful. It protects the founder in the worst-case scenario.
• Cap and floor are negotiated together. A low cap (favorable to the investor) can be offset by a floor (favorable to the founder).

Worked example: a conversion scenario with a 20% discount and a €3M cap

Let's take a concrete case to understand the mechanics:

Starting point:

• BSA Air investment: €100,000
• Discount: 20%
• Cap: €3,000,000
• Floor: €1,500,000
• Number of existing shares: 10,000

Scenario A: Qualified round at €5M pre-money valuation

The cap applies (€5M > €3M cap):

• Price per share at the round: 5,000,000 / 10,000 = €500
• BSA Air price per share (based on the cap): 3,000,000 / 10,000 = €300
• Then the discount: €300 × (1 − 20%) = €240
• Shares received: 100,000 / 240 = 417 shares
• Without a BSA Air, €100,000 at the round price = 200 shares

The BSA Air investor receives 2× more shares than a round investor. The cap combined with the discount doubles their advantage.

Scenario B: Qualified round at €2M pre-money valuation

The floor applies (€2M > €1.5M floor, but < €3M cap, so no cap):

• Price per share at the round: 2,000,000 / 10,000 = €200
• BSA Air price per share (discount only): €200 × (1 − 20%) = €160
• Shares received: 100,000 / 160 = 625 shares

Scenario C: Downround at €1M pre-money valuation

The floor applies (€1M < €1.5M floor):

• BSA Air price per share (based on the floor): 1,500,000 / 10,000 = €150
• Discount: €150 × (1 − 20%) = €120
• Shares received: 100,000 / 120 = 833 shares
• Without a floor, based on €1M: 100,000 / (100 × 0.8) = 1,250 shares

The floor saved the founder from handing over 1,250 shares instead of 833. For an early-stage startup, that difference can amount to several points of dilution.

Benefits and limits of the BSA Air

The BSA Air is not a miracle tool. It solves a specific problem (raising fast without a valuation) but creates constraints you need to anticipate.

For the startup: speed, simplicity, no immediate valuation

The benefits:

• Speed. 1 to 3 weeks versus 3 to 6 months for a traditional round. This is the whole point of the BSA Air.
• Legal simplicity. A 5- to 15-page contract, limited formalities, and lower legal fees (€1,500 to €5,000 versus €10,000 to €20,000 in a traditional round).
• No immediate valuation. You don't set a price on your company while it's still too young to be valued properly. The valuation is set at the next round, once you have traction.
• Keeping control. The BSA Air investor has neither voting rights nor a board seat until conversion happens.

For the investor: discount, protection, early-stage access

The benefits:

• Guaranteed discount. The investor knows they'll pay less than the investors in the following round. It's the reward for taking on risk.
• Cap (optional). If the startup takes off, the cap limits the conversion price and maximizes the return.
• Early-stage access. The BSA Air makes it possible to invest in startups that aren't yet ready for a formal round, opening the door to opportunities that would otherwise be out of reach.
• Favorable tax treatment. As a transferable security, the BSA Air qualifies for the securities capital-gains regime. It can be held in a PEA-PME under certain conditions.

The limits: potential dilution, conversion complexity

The risks on the founder's side:

• Surprise dilution. If the next round happens at a low valuation, the BSA Air (with its discount, plus a cap if there is one) can generate significant dilution. Always model the conversion scenarios on your cap table before signing.
• Stacking. Several successive BSA Airs (bridge, re-bridge) create complexity at conversion. Series A investors take a dim view of a cap table loaded with unresolved convertibles.

The risks on the investor's side:

• No shareholder status. Until conversion happens, the BSA Air investor isn't a shareholder. No voting rights, no information rights, no board seat.
• Non-conversion risk. If the startup never raises and finds no buyer, the investment can be lost. The deadline offers partial protection, but forced conversion at a floor can hand over shares worth very little.
• Friction at the next round. Series A investors sometimes lump BSA Air investors in with friends and family and don't invite them to the negotiating table. It's a recurring point of friction.

Setting up a BSA Air: a practical guide

Let's move from theory to practice. Here's the concrete process for issuing BSA Airs.

When to use a BSA Air (bridge, pre-seed, between rounds)

The BSA Air is the right tool in three situations:

1. Pre-seed (€100K - €500K). You're just starting out, you have no credible valuation, and one or more business angels want to invest. The BSA Air has become the de facto standard for pre-seed rounds of €100,000 to €1 million in France, especially when they're led by business angels and micro-funds.

2. The bridge (between rounds). You've raised a seed, runway is shrinking, and the Series A isn't closed yet. A BSA Air bridge gives you 6 to 12 months of extra cash without reopening valuation negotiations.

3. The fast opportunity. A strategic investor wants in now. The BSA Air lets you secure the funds in a matter of days, without waiting for a formal round to close.

When a BSA Air is the wrong choice:

• If you can set a reasonable valuation, do a traditional equity round instead.
• If the amount exceeds €1-2M, investors will want shares and governance rights.
• If you already have 3+ unconverted BSA Airs, clean things up before adding more.

The concrete steps (EGM, issuance, subscription)

Step 1: Prepare the terms. Negotiate with your investor: amount, discount, cap, floor, deadline, minimum trigger event. Document everything in a simple term sheet (1-2 pages).

Step 2: Draft the documents.

• President's report (or EGM minutes) authorizing the issuance
• Subscription form
• BSA Air contract (terms and conditions)

Options: a specialist lawyer (€1,500 to €5,000) or an online platform like SeedLegals (configuration, automatic generation, electronic signatures).

Step 3: General meeting (or delegation). The EGM votes to authorize the issuance of the BSA Airs. If the president holds an existing delegation, they can issue them directly.

Step 4: Signature and transfer. The investor signs the subscription form and transfers the funds. The BSA Airs are issued and recorded in the share transfer register.

Step 5: Post-issuance formalities. Update the share transfer register, inform existing shareholders, and keep the documents on file.

What it costs (legal fees, timelines)

Compare that with a traditional fundraise: €10,000 to €25,000 in legal fees and a 2- to 4-month process. The BSA Air costs 3 to 5 times less and moves 4 to 8 times faster.

Best practices from recent case law

Case law on BSA Airs is still limited in France, but several rulings and field experience point to a set of best practices:

1. Keep BSA Air holders informed. Even though they aren't shareholders, courts consider that they have a legitimate right to be informed of major events (a round, an acquisition, a change of control). Include an information clause in the contract.

2. Document the financial situation. In a conversion dispute, a clear trail of accounts and decisions is decisive. Keep your books up to date and document issuance decisions.

3. Invite holders to the conversion meeting. Bring BSA Air holders to the general meeting that decides on the conversion. It isn't always mandatory, but it's a best practice that heads off disputes.

4. Model the cap table before issuing. Use a simulator (SeedLegals, Carta, or a plain spreadsheet) to see the impact of conversion across different scenarios. Dilution surprises happen when nobody ran the numbers in advance.

5. Limit the number of simultaneous BSA Airs. Past 2-3 unconverted BSA Airs, the legal and financial complexity climbs and Series A investors get nervous. Convert or consolidate before issuing new ones.

Going further

• Top 15 VCs in Paris: a guide for startups
• Raising a seed round
• Business angels: how to find them

FAQ

What is a BSA Air?

The BSA Air (Bon de Souscription d'Actions, Accord d'Investissement Rapide) is a financial instrument that lets a startup raise funds quickly without setting a valuation. The investor transfers the money immediately and receives warrants that convert into shares at a future event (a fundraise, an acquisition), with a discount of 15 to 25% on the share price. It's the French adaptation of the American SAFE, created in 2013.

What discount should you plan for with a BSA Air?

The standard discount is between 15 and 25% off the price per share at the qualified round. 20% is the most common rate. 15% for low-risk situations (a round expected within 6 months, a startup with traction). 25% for high-risk situations (a very early-stage startup, a long conversion horizon). Beyond 25%, the investor is taking on significant risk, and it's often better to consider an equity round at a low but fixed valuation.

What's the difference between a BSA and a BSA Air?

A classic BSA is a fixed-price warrant: the exercise price is set at issuance. It's mainly used to incentivize advisors or strategic partners. A BSA Air is a warrant whose conversion price "floats": it's set at the trigger event (a qualified round), with a discount applied. The BSA Air is used to raise funds quickly without valuing the company. The "Air" (Accord d'Investissement Rapide, "fast investment agreement") refers to the speed of the process.

How are BSA Airs taxed?

BSA Airs qualify for the tax regime of transferable securities. The capital gain realized when the shares (from converting the BSA Airs) are sold is subject to the 30% PFU (Prélèvement Forfaitaire Unique, the flat tax), or, by election, to the progressive income tax scale with holding-period allowances. Under certain conditions, BSA Airs can be held in a PEA-PME, which offers a capital-gains tax exemption after 5 years of holding (excluding the 17.2% social levies).

How long does it take to set up a BSA Air?

1 to 3 weeks between negotiating the terms and transferring the funds. With an online platform (SeedLegals), the process can be wrapped up in 2 to 5 business days. With a specialist lawyer, count on 1 to 2 weeks for drafting and signing. The legal formalities (registration in the register, court registry) take an extra week. That's 4 to 8 times faster than a traditional fundraise, which typically takes 2 to 4 months.

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