BSA AIR in France 2026: advantages, risks and tax for founders

The BSA AIR has become one of the most widely used early-stage financing instruments in France. Its mechanics are straightforward: the investor commits funds today, and conversion into shares takes place later, on the basis of a formula or a trigger event defined in the contract. That flexibility appeals to founders who want to raise quickly without anchoring a valuation too early in the company's development.

But this is a technical instrument. Insufficient documentation, an ambiguous conversion formula, or a tax angle that has not been properly considered can turn a structural advantage into a source of friction at exactly the wrong moment — the next fundraising round. Understanding what you are signing, before you sign it, is not optional.

A BSA AIR — bon de souscription d'actions avec accord d'investissement rapide — is not a debt instrument. It is a securities law instrument giving the investor the right to subscribe for shares at a future date or upon a trigger event. It is reserved for joint-stock companies (sociétés par actions), in practice almost always the SAS (société par actions simplifiée). Valuation is not fixed at issuance: it will be determined at a future qualifying round, typically with a discount or a valuation cap in favour of the early investor.

The BSA AIR is issued by the company to an investor in exchange for an immediate cash contribution. Conversion into shares is not automatic — it is conditional on a trigger event, typically a qualifying financing round above a threshold, a sale of the company, or a longstop date.

Two mechanisms typically protect the investor:

• The discount: the investor subscribes for shares at a price below the qualifying round price (often 15–25%, depending on the specific contract).
• The valuation cap: if the qualifying round valuation exceeds an agreed ceiling, the investor converts on the basis of that cap — limiting dilution and securing the return on risk taken early.

For the company, the benefit is avoiding a premature valuation discussion in an uncertain context. For the investor, the compensation for taking early risk is built into the conversion mechanics.

The primary advantage is speed. When a fundraising timeline is tight, the BSA AIR allows an investment ticket to be secured quickly — without going through all the steps of a conventional capital round: valuation negotiation, detailed term sheet, full shareholders' agreement. Those steps take time and management attention that an early-stage company often cannot afford.

The second advantage is flexibility on valuation. In the earliest phases of development, fixing a valuation can be counterproductive. Too low, and founders dilute themselves excessively. Too high, and the next round becomes harder to close at a higher price. The BSA AIR defers this debate to a point when the company has more data to work with.

Benefits seen in early-stage files#

• Execution in days rather than weeks.
• Legal cost typically lower than for a fully structured round.
• Readability for business angels familiar with bridge financing mechanics.
• Ability to tie conversion to a genuine development milestone — first recurring revenue, first major contract, validated product.

For a startup still in the market-validation phase, this can be highly effective. The question is not the instrument itself but the precision with which it is drafted.

A BSA AIR creates a deferred obligation — not unlimited flexibility. The most common risks seen in early-stage files fall into three categories.

Approximate documentation. A vague conversion formula, a poorly defined trigger event, or an imprecise timeline generate disputes at the worst possible moment — when Series A investors arrive and begin reviewing the cap table history. Any ambiguity in the conversion mechanics becomes a blockage point.

Dilution that was not modelled. Founders who sign quickly without simulating the combined effect of the discount and valuation cap across different scenarios sometimes face higher dilution than expected. That is not a problem in itself if it was anticipated — but it becomes one if it was not.

Coordination with the shareholders' agreement. A BSA AIR signed without alignment with the existing pacte d'associés can create governance friction. If the BSA AIR investor has no clearly defined information rights before conversion, tensions can emerge.

Most common mistakes seen in practice#

• Using a generic template without adapting it to the company's actual situation.
• Failing to include a protective clause in the event that the next round falls below the qualifying threshold.
• Not modelling the cap table with and without conversion, across multiple valuation scenarios.
• Confusing BSA AIR with a convertible loan or with BSPCEs — which follow an entirely different legal and tax logic.
• Underestimating the effect of the valuation cap in a rapid-growth scenario.

Our read: a well-drafted BSA AIR protects both the founder and the investor. Speed of execution is an advantage — not an argument for skipping legal and accounting review.

The comparison is frequent, and so is the confusion. The SAFE (Simple Agreement for Future Equity) is a US-origin instrument, popularised by Y Combinator. It is based on a sui generis contract with no direct equivalent in French law.

For a French company structured as a SAS, the BSA AIR offers a stronger legal footing and a more clearly defined tax framework than an adapted SAFE. Both instruments pursue the same goal — accelerating an investor's entry without fixing valuation — but their legal and tax treatment diverges in ways that matter in practice.

The BSA AIR does not carry a dedicated statutory tax regime. Tax treatment is analysed according to the nature and qualification of the gain realised — which requires a case-by-case analysis.

As a general rule, the gain realised by the investor upon disposal of the shares received on conversion is treated as a capital gain on securities (plus-value sur valeurs mobilières). For an individual investor resident in France, this gain is subject to the flat tax (prélèvement forfaitaire unique, PFU) at 31.4% since 1 January 2026 — comprising 12.8% income tax and 18.6% social levies (following the 1.4-point increase in the CSG under the LFSS 2026). The option to apply the progressive income tax scale remains available if it produces a lower charge.

This is a general presentation. The effective rate depends on the investor's personal situation, the holding period, the precise qualification of the instrument, and the structuring of the transaction. Corporate investors — funds, holding companies — are subject to a different treatment.

The primary risk: reclassification#

The real tax risk in a BSA AIR is not the rate — it is reclassification. If the transaction does not reflect genuine investment logic, if the entry price is manifestly undervalued, or if the instrument resembles a disguised form of remuneration, the French tax authority may reclassify the gain as ordinary income, subject to progressive income tax rates and social contributions.

Administrative doctrine on securities transactions outside statutory employee shareholding schemes (dispositifs légaux d'actionnariat salarié) — set out in the BOFiP — makes clear that qualification depends on the facts, not on the label given to the document.

Three points to verify before issuance:

1. The economic coherence of the entry price and the discount.
2. The absence of any link between the BSA AIR and an employment or service relationship.
3. The compliance of the documentation with the Code de commerce rules governing BSAs.

These three instruments look similar on the surface but serve distinct purposes.

• The BSA AIR is an early-stage financing tool for external investors, designed to accelerate capital entry without fixing valuation.
• The standard BSA is a more conventional share subscription warrant, typically used in financing or partnership contexts, with valuation defined at issuance.
• The BSPCE (bon de souscription de parts de créateur d'entreprise) follows a specific statutory regime. It is reserved for eligible employees and managers of qualifying young companies (article 163 bis G CGI). Its tax treatment is distinct and specifically regulated — and was reformed by the 2025 Finance Act.

Confusing BSA AIR with BSPCEs is a frequent and costly mistake. BSPCEs in 2026 operate under a specific reformed tax regime — the two instruments are not interchangeable. See also our comparative analysis of BSA AIR, BSPCEs and free shares for retaining talent.

A SAS in the development phase raises €200,000 from a business angel via BSA AIR. The main contract parameters:

• 20% discount on the price of the next qualifying round.
• Valuation cap: €3,000,000.
• Trigger event: a financing round of at least €500,000, or a sale of the company.

Scenario A — Seed round at €4,000,000 post-money valuation: The valuation cap applies (valuation exceeds the cap). The investor subscribes on the basis of €3,000,000. For €200,000, the investor receives approximately 6.7% of the capital (€200,000 / €3,000,000). Without the cap, they would have received only 5% (€200,000 / €4,000,000). The cap added 1.7 percentage points of ownership.

Scenario B — Seed round at €2,000,000 post-money valuation: The valuation is below the cap. The 20% discount applies: the investor subscribes at €2,000,000 × 0.80 = €1,600,000. For €200,000, the investor receives 12.5% of the capital. A founder who did not model this scenario may discover significantly higher dilution than anticipated.

This example is simplified and does not account for existing shares, preferential rights, or anti-dilution clauses. It illustrates why cap table modelling before signature is not optional.

Before issuing a BSA AIR, the following questions deserve written, non-approximate answers:

• What is the precise financing objective and anticipated timeline?
• What trigger event is chosen, and what happens if it does not occur within the agreed period?
• What is the discount and what is the valuation cap — have they been modelled across multiple valuation scenarios?
• How does conversion interact with the rights of existing shareholders?
• Will the BSA AIR investor have information rights, pre-emption rights, or other protections before conversion?
• Is the structure compatible with JEI status (article 44 sexies-0 A CGI) if the company is seeking that designation?

JEI status conditions significant tax and social-levy exemptions. A complex or poorly documented capital structure can create difficulties when eligibility is reviewed.

If you are preparing your pre-seed or Series A fundraise, the BSA AIR structuring is part of a broader reflection on term sheet clauses and negotiation.

Before signing, one simple question tests the robustness of the document: if the next round happens twice as fast as the central scenario, or if the valuation is twice as high, does the BSA AIR remain coherent for all parties? If the answer is uncertain, the contract needs to be revisited.

The chartered accountant (expert-comptable) does not draft the BSA AIR — that is the lawyer's role. But the accountant contributes usefully across several dimensions:

• Financial modelling: cap table before and after conversion, across multiple valuation scenarios.
• Economic coherence review: verifying that the entry price and parameters (discount, cap) reflect genuine investment logic.
• Tax analysis: identifying reclassification risks and the points that need to be secured in the documentation.
• JEI compatibility check: confirming that the capital structure does not jeopardise access to innovation tax and social-levy exemptions.
• Data room preparation: organising accounting and tax documentation for the next round.

These contributions are complementary to the lawyer's work, not a substitute for it. A solid BSA AIR rests on coordination between both advisers.

Secure your startup structuring · Accounting and tax support for startups

Last updated 2026-06-14. This article is for information purposes and does not replace personalised advice. For your specific situation, consult a chartered accountant registered with the Ordre des Experts-Comptables.