Photo par imo.un via Flickr (CC BY 2.0)In brief:
- SAS gives its president an employee-like social regime, SARL puts the majority manager under the self-employed regime.
- SASU and EURL are the single-shareholder versions of SAS and SARL.
- The self-employed regime costs on average 25 to 30% less in contributions than the employee-like regime.
- SAS bylaws can be drafted more freely than SARL bylaws, which are framed by the Commercial Code.
Why the legal structure is a defining decision
The legal structure chosen at start-up determines the manager’s social security regime, governance rules, and by default the company’s tax regime. Changing it later remains possible but involves formalities and costs.
The main decision criteria
Three questions help decide quickly: how many partners at the start, which social regime for the manager(s), and how much formality is wanted in governance.
SAS and SASU: flexibility and an employee-like regime
SAS (or its single-shareholder version, SASU) allows tailor-made bylaws: distribution of power, approval clauses, exit terms for partners. The president falls under the general social security scheme, like an employee, but without unemployment insurance.
Comparing social security cost
| Structure | Manager’s social regime | Indicative social contributions |
|---|---|---|
| SASU / SAS | Employee-like | ~ 65 to 75% of net pay |
| EURL / SARL | Self-employed | ~ 40 to 45% of net pay |
SARL and EURL: a stricter framework, lower charges
SARL follows a stricter legal framework set by the Commercial Code, which limits freedom in the bylaws but simplifies certain standard decisions. The majority manager falls under the self-employed social regime, generally cheaper in contributions.
“The manager’s social security regime remains one of the most decisive criteria in choosing between SAS and SARL, even before the tax question.” — service-public.fr, 2026
How to decide in practice
- List the number of partners expected from the start and in the medium term
- Compare the manager’s net pay under each social regime for the same gross salary
- Check whether either structure limits a future holding company project
This choice also connects with the registration and Kbis process, and with the taxation covered in the guide on the CFE local business tax.
Frequently asked questions
What is the difference between SAS and SARL?
SAS allows broad freedom in drafting its bylaws and places its president under the employee-like social regime, while SARL follows a stricter legal framework and puts the majority manager under the self-employed social regime.
Can a SASU be turned into an SAS?
Yes, a new partner joining a SASU automatically turns it into an SAS, without a formal conversion procedure as such, only an update to the bylaws and the Kbis certificate.
Is the self-employed regime always cheaper?
Generally yes for the same level of pay, but the employee-like regime grants social rights closer to those of a standard employee, which can offset the extra cost depending on the manager’s priorities.