Running a micro-business alongside a company: rules and limits

You manage a French SARL or SASU, or have just set one up, and you would like to keep your micro-business (micro-entreprise) running on the side. The real question is not only "is it allowed?" but "under what conditions does the combination stay sound from a social security, tax and criminal law standpoint". Everything depends on a genuine separation between the two activities and on the money flowing between them.

Quick answer. Running a micro-business alongside a company is legal in France in 2026: one person may hold a single micro-entreprise while managing or owning an SARL or SAS. Each activity bears its own social contributions (micro rates from 12.3% to 25.6% of turnover), and the main risk arises when the micro-business invoices the company you manage.

This article covers the long-term coexistence of both structures. If your question is rather when to give up the micro-business in favour of a company, read our analysis of when to switch from a micro-business to a company.

Having a micro-business and a company at the same time is possible, because no French rule prevents a micro-entrepreneur from being a shareholder, manager (gérant) or chair (président) of a company. A micro-entreprise is a sole proprietorship (entreprise individuelle) under a simplified tax and social security regime; a company is a separate legal entity with its own assets, its own accounts and its own taxation.

There is one limit on the micro side: according to economie.gouv.fr, an individual may hold only one micro-entreprise. That person may, however, carry on several activities within it, even unrelated ones (so-called mixed activity), provided the main and secondary activities are declared on the single business formalities portal (guichet unique).

In practice, the combination takes three forms:

• Non-managing shareholder: you hold shares and may receive dividends, without holding a corporate office.
• Majority manager of an SARL or EURL: you are self-employed (travailleur non salarié, TNS) for the management role, and self-employed for the micro-business.
• Chair of an SAS or SASU, or minority or equal manager of an SARL: you are treated as an employee (assimilé salarié) for the paid corporate office, and self-employed for the micro-business.

The choice of company form therefore directly shapes your social security position. Our comparison of SASU and EURL covers this on the company side; here, we focus on what the micro-business adds.

An SARL manager can also be a micro-entrepreneur (auto-entrepreneur), whether majority or minority, provided the manager respects the duty of loyalty owed to the company and any clauses in the articles of association or shareholders' agreement. French law sets no general incompatibility between managing an SARL and running a personal self-employed activity.

A majority SARL manager falls under the self-employed social security scheme (Sécurité sociale des indépendants) for the management role, as Urssaf points out. According to the self-employed social protection website (CPSTI), people carrying on several activities at the same time are affiliated with, and contribute simultaneously to, the schemes covering each of those activities.

Our view#

At the firm, we consider that the real issue is almost never whether the combination is legal, but where the boundary between the two activities lies. As long as the micro-business sells to its own clients, in a distinct line of work, the combination is simple. As soon as the micro-business and the company share clients, a trade or money flows, the file becomes a matter of governance and evidence.

Social contributions for a business owner combining a micro-business and a company are due in each scheme, activity by activity, with no offsetting between them. The micro-business pays a percentage of the turnover it collects; the manager's pay bears the contributions attached to that person's status in the company.

Two practical consequences follow. First, an unpaid SASU chair does not contribute in respect of the corporate office: social protection then rests on the micro-business alone, which is often thin. Second, a majority manager who combines two self-employed activities pays self-employed contributions twice, on two different bases. Our article on choosing between self-employed (TNS) and assimilé salarié status explains both schemes.

Taxation of a combined micro-business and company layers two separate charges: the flat-rate profit of the micro-business is added, in your personal income tax return, to the pay and dividends you draw from the company. According to impots.gouv.fr, the micro regime applies a flat allowance of 71% (purchase for resale), 50% (BIC services) or 34% (BNC), with a minimum of €305.

On the company side, the manager's pay is taxed as employment income (traitements et salaires), and dividends are subject by default to the 12.8% flat tax (prélèvement forfaitaire unique) plus 18.6% social levies, i.e. 31.4% in total in 2026, unless you opt for the progressive scale across all such income.

The flat-rate income tax option, a classic trap#

The flat-rate income tax option (versement libératoire) allows a micro-entrepreneur to pay income tax together with social contributions, at 1% (sales), 1.7% (BIC services) or 2.2% (BNC) of turnover. According to impots.gouv.fr, opting for 2026 required a 2024 household reference tax income (revenu fiscal de référence, RFR) not exceeding €29,315 per family quotient share.

The underestimated risk lies here: the reference tax income includes the salaries and dividends received from the company. A business owner who starts drawing pay from the company can lose access to the flat-rate option on the micro-business two years later, without changing anything in the micro-business itself. For the option to apply from 1 January of a given year, the request must reach Urssaf by 30 September of the previous year; the threshold applicable for 2027, based on 2025 income, is subject to confirmation by the official publication.

Micro regime thresholds are assessed at the level of the micro-business itself: the company's turnover, as a separate legal entity, falls under its own taxation. For 2026 to 2028, Urssaf states ceilings of €203,100 for the sale of goods and €83,600 for services, with an overall ceiling of €203,100 for mixed activity.

The VAT basic exemption (franchise en base de TVA) follows the same logic of a separate taxable person. According to the BOFiP (BOI-TVA-DECLA-40-10-10 of 1 July 2026), it applies if the previous year's turnover does not exceed €85,000 for sales and €37,500 for most services. The company applies its own VAT regime.

Points to watch#

Artificially splitting a single activity between the micro-business and the company to stay under the micro thresholds or the VAT exemption exposes you to a challenge. If both structures sell the same thing to the same clients using the same resources, the authorities may see a single economic activity carved up for tax reasons. The combination holds up when each activity has its own rationale. The detailed ceilings are set out in our article on micro-business ceilings and rules in 2026.

The main risk of combining two activities appears when the micro-business invoices the company you manage or own. Such invoicing is not prohibited, but it concentrates four legal and tax risks that must be dealt with before the first invoice.

1. The related-party agreement (convention réglementée). An agreement between the company and its manager, concluded directly or through an intermediary, falls under the related-party agreement procedure: article L223-19 of the French Commercial Code for an SARL (report submitted to the shareholders' meeting, a simple entry in the decisions register for a single-shareholder company), article L227-10 for an SAS. Ordinary agreements concluded on normal terms are exempt.
2. The abnormal management act (acte anormal de gestion). An abnormal management act is an expense incurred by the company in an interest other than its own. An overpriced service billed by your micro-business may see its cost disallowed in the company; our article on transactions that amount to an abnormal management act explains the mechanism.
3. Misuse of corporate assets (abus de biens sociaux). Misuse of corporate assets is the bad-faith use of the company's property or credit against its interest, for personal purposes or to favour a business in which the manager has an interest. It carries five years' imprisonment and a €375,000 fine (article L241-3 of the French Commercial Code for an SARL, article L242-6 applying to an SAS chair by reference from article L244-1).
4. Fictitious invoices and social security abuse of law. An invoice with no real service behind it is a false invoice. And if invoicing through the micro-business mainly serves to replace pay for the corporate office that would bear heavier contributions, Urssaf may invoke abuse of law (article L243-7-2 of the French Social Security Code), with a penalty of 20% of the contributions due.

There is also a governance risk: a manager owes a duty of loyalty to the company. Running a competing activity through the micro-business, or diverting the company's clients, may justify removal from office and a liability claim, regardless of any non-compete clause.

Permitted or risky combination: the decision table#

The related question of a micro-business working as a subcontractor for another company, outside any management link, is covered in our article on micro-entrepreneurs and subcontracting.

Securing the combination of a micro-business and a company means making the separation of the two activities visible to a third party: bank, Urssaf, tax authorities or co-shareholder. The following steps cover the essentials.

In practice#

1. Describe each activity. Write one sentence for the purpose of the micro-business and one for the company; if the two sentences look alike, the combination deserves a second look.
2. Reread the articles and shareholders' agreement. Check the corporate purpose, exclusivity or non-compete clauses and the rules on related-party agreements.
3. Separate resources. Bank accounts, invoices, tools, billing address and, where possible, client base kept apart.
4. Frame any internal invoicing. Written contract, price backed by market references, deliverables kept on file, related-party procedure followed.
5. Recalculate your overall taxation. Model the effect of salary and dividends on your reference tax income and on access to the flat-rate option.
6. Review the situation every year. Weight of the micro-business in your income, share of turnover made with the company, changes in thresholds.

Checklist before keeping your micro-business#

• A single micro-entreprise in your name, secondary activities declared
• Purpose of the micro-business distinct from the company's actual activity
• No exclusivity clause in the articles or contracts breached
• Two bank accounts and two separate invoice number sequences
• Every invoice from the micro-business to the company backed by a contract and a deliverable
• Related-party agreement procedure followed when the agreement is not ordinary
• Reference tax income checked before opting for the flat-rate income tax option
• Micro thresholds and VAT exemption monitored activity by activity

Trade-off: keep the micro-business or bring everything into the company?#

Keeping the micro-business makes sense when the activity is ancillary, distinct and low in costs: the simplicity of the regime remains a real advantage. Bringing the activity into the company makes sense when the micro-business becomes the company's main supplier, when clients overlap, or when actual costs exceed the flat-rate allowance. If the new activity deserves a structure of its own, our guide to setting up a second company, subsidiary or holding presents the group options.

• Running a micro-business alongside a company is legal, within the limit of one micro-entreprise per person.
• Each activity pays contributions under its own scheme: micro-social on turnover, self-employed or general scheme on the manager's pay.
• Salaries and dividends from the company count towards the reference tax income and can close off access to the flat-rate income tax option.
• Micro thresholds (€203,100 and €83,600 for 2026 to 2028) and the VAT exemption are assessed structure by structure, without permitting an artificial split.
• The hard point is a micro-business invoicing its owner's company: related-party agreement, abnormal management act, misuse of corporate assets, social security abuse of law.