From sole trader to SASU: 2026 rules and calculations

Quick answer. There is no automatic conversion: you close the micro-enterprise and then set up the SASU. You usually make the move when turnover approaches the micro ceilings (83,600 euros for services, 203,100 euros for sales), when you need to reclaim VAT and deduct real costs, or to manage salary and dividends (flat tax of 31.4 % in 2026).

The French micro-enterprise (auto-entrepreneur) regime is excellent for getting started: light formalities, ultra-simplified accounting, contributions calculated on collected turnover. But it quickly reaches its limits as activity grows. The question is then no longer how to set up a micro, but when and how to switch to a company. The SASU is the form most often chosen by self-employed professionals stepping up.

This article does not repeat how to create a micro or a SASU in isolation. It deals with the transition itself: the quantified triggers, the tax and social comparison, the practical procedure, and the salary-dividend trade-off once the company is up and running. For the general framework of the starting regime, see also what you need to know about the sole-trader status.

The first reflex is to look at the micro turnover ceilings. For 2026, 2027 and 2028 they are set at 203,100 euros for the sale of goods and accommodation, and 83,600 euros for services (BIC or BNC). For mixed activity, total turnover must not exceed 203,100 euros, of which a maximum of 83,600 euros for the services portion.

But the turnover ceiling is not the only trigger, nor even the most frequent. In practice, VAT often forces the decision well before those levels. The VAT-exemption thresholds are much lower: 85,000 euros for sales and 37,500 euros for services, with tolerance thresholds at 93,500 euros and 41,250 euros (Act of 3 November 2025). A service provider can therefore become liable for VAT from 37,500 euros of turnover, while still far from the 83,600-euro micro ceiling.

Here are the triggers we most often see in transition files:

• Turnover approaches or exceeds the micro ceilings (203,100 or 83,600 euros).
• Activity crosses the VAT threshold and the basic exemption disappears: accounting becomes more complex and the inability to deduct costs becomes penalising.
• Real costs become heavy (subcontracting, purchases, equipment, rent) and the flat-rate micro allowance no longer reflects economic reality.
• The need to protect personal assets appears, as the micro offers no limited liability on the activity.
• Bringing in partners or investors is being considered, which is impossible in a micro.

Our note on crossing the VAT threshold as a sole trader details the immediate consequences, and how the basic VAT exemption works sets out the rules.

Under the basic exemption, you do not charge VAT but you cannot reclaim it either. As long as your purchases are low, this is comfortable. As soon as you invest (equipment, subcontracting, services) or your clients are themselves professionals who reclaim VAT, the exemption becomes a handicap: you bear non-deductible input VAT that a SASU under the real regime could reclaim.

In 2026, the single threshold of 25,000 euros that had been considered was abandoned: the Act of 3 November 2025 keeps the thresholds at 85,000 euros (sales) and 37,500 euros (services). Beyond the tolerance threshold during the year (93,500 or 41,250 euros), VAT becomes due from the first day of the month of crossing. Anticipating this moment avoids a sudden adjustment.

Under the micro, tax is calculated on turnover after a flat-rate allowance: 71 % for sales, 50 % for BIC services, 34 % for BNC and liberal professions, with a minimum allowance of 305 euros. No real cost is deductible and no VAT is recoverable. The 2026 social contributions (full rates) reach 12.3 % for sales, 21.2 % for BIC services and 25.6 % for BNC and other services. From 1 July 2026, the vocational training contribution is added: 0.10 % for traders, 0.20 % for liberal professions, 0.30 % for craftspeople.

In a SASU, profit is taxed under corporate income tax: 15 % up to 42,500 euros of profit if turnover stays below 10 million euros and at least 75 % of the capital is held by individuals, then 25 % above (French Tax Code, article 219, I-b). Under the real regime you deduct costs, depreciate investments and reclaim VAT. The SASU president is treated as an employee and falls under the general social-security scheme: in the absence of remuneration, no minimum contribution is due.

Our reading. The switch is not just a matter of ceiling. It becomes relevant when one of three levers fires: non-recoverable VAT is costly, real costs far exceed the flat-rate allowance, or separating business and personal assets becomes an issue. As long as none of these levers is active and costs stay low, the micro often keeps the advantage of simplicity. To structure this reasoning, the legal-status decision tree is a good starting point.

You need to understand that there is no legal conversion of a micro into a company. The micro-enterprise is a sole proprietorship: you cease it, then you create a separate company. The sequence is as follows:

1. Check the case and timing with a chartered accountant (quantified gain, switch date, handling of ongoing contracts).
2. Set up the SASU: drafting the articles of association, depositing the share capital in a dedicated account, publishing a legal notice, registering with the RNE and RCS through the INPI single window.
3. Where relevant, contribute the business or client base of the micro to the company (contribution in kind, with or without valuation depending on scope).
4. Cease the sole-trader activity: free deregistration through the INPI single window, with the associated cessation filings.
5. Set up real-regime accounting, VAT, and the president's payroll if remuneration is paid.

Deregistering the micro is free. Creating the company, however, generates costs: legal notice, registry fees, possible contribution costs, and advisory fees depending on scope. Our support for company formation covers this sequence end to end, and our bookkeeping and accounts review offering takes over for real-regime accounting. To revisit the obligations of the starting regime, see the accounting obligations of the micro-enterprise.

In practice. Preferably choose a switch date at the start of the calendar year to avoid running an intertwined micro year and company year on the same year. Remember to move billing, client and supplier contracts, the professional bank account and the management tool. Platforms such as Pennylane or Tiime make the transition to real-regime accounting easier.

The cost of the move comprises company formation (legal notice, registry fees, possible contribution costs) and advisory fees, which depend on scope: simple incorporation, contribution of a business, payroll set-up. Deregistering the micro costs nothing.

The move becomes economically justified when the recurring annual gain (reclaimed VAT, deducted costs, salary-dividend trade-off, reduced corporate-tax rate) durably exceeds the company's structural costs: accounting fees, the cost of any payslip, increased formalism. This is precisely the calculation we run file by file, because it depends on the cost structure and the desired level of remuneration.

Once in a SASU, the director arbitrates between salary and dividends. The president's remuneration bears social contributions (general scheme, employee-treated) but opens social rights and remains deductible from the company's profit. Dividends, on the other hand, are not subject to social contributions and are taxed under the single flat-rate levy of 31.4 % in 2026 (12.8 % income tax and 18.6 % social levies), or at the progressive scale by election.

Trade-off. The SASU has an advantage here over the EURL with a majority manager. In an EURL, the majority manager is self-employed and the share of dividends above 10 % of the share capital is subject to social contributions. In a SASU, dividends fully escape social contributions, whatever their amount relative to capital. For a self-employed person planning to distribute dividends regularly, this point weighs in the choice between the two forms. Our business taxation advice quantifies this trade-off for your situation.

Not every profile gains from switching. Here are the situations that deserve specific review:

• Low-cost activity with private clients. If you have almost no deductible costs and your clients do not reclaim VAT, the basic exemption remains an asset and the micro keeps the advantage.
• Subcontracting. A self-employed person subcontracting for professional principals often benefits from reclaiming VAT and deducting costs: the topic is detailed in our article on sole traders and subcontracting.
• ACRE. The first-year partial contribution exemption is not transferable: if you obtained it under the micro, it does not mechanically carry over into the company. Since 2026, under the micro, the ACRE claim is filed with Urssaf within 60 days and is no longer automatic.
• EURL rather than SASU. Depending on the level of remuneration and the share of dividends targeted, the EURL under the self-employed regime can, in some cases, be cheaper in contributions. This is a trade-off to be quantified, not a general rule.

• VAT: the real trigger. Watch the 37,500-euro threshold (services) or 85,000-euro threshold (sales) more than the micro ceiling: VAT becomes due from the first day of the month in which the tolerance threshold is crossed.
• Single threshold abandoned. The single-threshold project at 25,000 euros was not adopted: the 85,000 / 37,500-euro thresholds are confirmed by the Act of 3 November 2025.
• ACRE not automatic. Under the micro, since 2026, ACRE must be claimed from Urssaf within 60 days.
• Switch date. A mid-year switch means running two regimes over the same year: a badly timed schedule weighs down the accounting.

The underestimated risk. Many self-employed people switch too late, after crossing the VAT threshold without noticing, and discover a retroactive adjustment. Others switch too early, while their costs remain low, and bear structural costs higher than the gain. The right timing is calculated, not guessed.

In a recent file, a service consultant came to us at 70,000 euros of turnover, convinced he had to switch because he was approaching the 83,600-euro micro ceiling. The analysis showed the opposite: he had already been liable for VAT since the 37,500-euro threshold, but without charging it, which exposed his business to an adjustment. The priority was therefore not the micro ceiling but VAT compliance, then the calculation of the real gain from switching to a SASU given his low costs. The decision was made on figures, not on intuition.

As a chartered accountant registered with the Order of Chartered Accountants of Île-de-France and a statutory auditor, we systematically quantify this type of trade-off before any decision, because each profile of costs and remuneration leads to a different answer. To go further on the timing of the switch, see our article on when to switch from micro to company.

Hayot Expertise tip. Before setting up the SASU, have two 12-month scenarios costed: staying in the micro with VAT, or switching to the real regime. The difference is measured above all on reclaimed VAT, deducted costs and the salary-dividend trade-off. The legal form is chosen after the costing, not before.