Definition
Julien is a salaried developer. A former classmate asks him to build a website, two weekends of work, 1,500 €.
He reads his contract again and finds an article he had never opened: the employee undertakes to devote his professional activity exclusively to the company.
Two opinions reach him straight away, that the clause is worthless and that it means certain dismissal. Neither is right.
A clause d'exclusivité (exclusivity clause) is the clause by which an employee undertakes to work for his employer alone, and to carry on no other professional activity while the contract lasts, whether salaried or self-employed.
It says nothing about what happens after leaving the company: that ground belongs to the non-competition clause.
It covers the life of the contract, and nothing beyond it. Nothing otherwise stops an employee from opening a Micro-enterprise: Combining with employment plays out between this clause, where it exists and is valid, and the duty of loyalty, which applies even with nothing written down.
The one-year window the law opens
This is the point most articles miss.
Article L1222-5 of the Code du travail (labour code) states that an employer may not rely on any exclusivity clause for one year against an employee who creates or takes over a business, even where the contract says otherwise.
The article does not say when the year starts: no starting date appears in it, and that gap is in the text itself.
It targets the creation or takeover itself, which points to counting from the declaration of start of activity filed with the One-stop shop, the one date you can prove.
An extended congé pour création d'entreprise (business creation leave) pushes the end back to the end of that extension.
Voyageurs, représentants et placiers, the statutory sales representatives, are the only ones left out.
Julien declares his activity on 1 March 2026: his clause is neutralised until 28 February 2027.
Over 2026 he collects 8,000 € from a non-regulated liberal activity, which falls under BNC (bénéfices non commerciaux, non-commercial profits) and belongs to the régime général, not to the Cipav.
His Social contributions are calculated at the 25.6% rate in force in 2026, so 2,048 €, leaving him 5,952 € once URSSAF has been paid.
That rate covers neither income tax nor the CFP, the contribution à la formation professionnelle or vocational training contribution.
The CFP is 0.2% of revenue in 2026 for a liberal activity.
It is only due where positive revenue was declared in the previous calendar year, so not in the first year, and it is added from 2027 onwards.
On the tax side, the 34% allowance applicable to micro-BNC in 2026 leaves 5,280 € added to his salary in the household return.
The CFE (business property tax) is not due for the year of creation, the year of the first revenue, and that is the only exemption granted as of right.
The trap: what the window does not suspend
The third paragraph of the same article leaves no room for doubt: the employee remains bound by the duty of loyalty.
It exists without any clause, it survives the neutralisation, and it ends only with the contract.
Approaching your employer's clients, working for yourself during working hours, using the company's equipment or files, invoicing while on sick leave or paid holiday: each of these is misconduct, clause or no clause.
The one-year window protects the act of creating, not the way you go about it. And it closes: once the year is up, a valid clause becomes enforceable again.
Two official pages tell different stories here.
The practical fact sheet on Service-Public, checked on 10 April 2026, states that an exclusivity clause in the contract makes the combination impossible, without mentioning the statutory neutralisation.
The labour code says it in black and white. When a practical page and a legal text disagree, the text decides.
Not to be confused with the non-competition clause
The two clauses differ in timing and in price. Exclusivity applies during the contract, covers any other activity even one unrelated to your trade, and gives no right to compensation.
Non-competition applies after the contract ends, covers competing activities only, must be limited in time and in area, and must come with financial compensation, failing which it is void.
Mixing them up leads people to give up on creating when nothing required it, or to feel free precisely when they leave the company.
An exclusivity clause is not valid simply because it was written down either.
It must be essential to protect the legitimate interests of the business, justified by the nature of the task, and proportionate to the aim pursued.
In a part-time contract, a blanket ban on working elsewhere deprives the employee of the means to earn a living, and is set aside.
Public-sector staff, finally, do not fall under the labour code: their situation is the one described in Civil servants and self-employment.
Frequently asked questions
Can my employer dismiss me because I set up a micro-enterprise?
Not on the basis of the clause alone during the year following the creation, since it cannot be relied on.
Dismissal becomes a real risk again where loyalty is breached, where the activity eats into working hours, or once the year has passed if the clause is valid.
Do I have to tell my employer before starting?
No text requires it for a self-employed activity carried on outside working hours.
Staying silent is not misconduct in itself, but it becomes untenable as soon as the activity comes close to the employer's market: better then to ask for something in writing, or an avenant (contract amendment) lifting the clause.
Can I invoice my own employer through my micro-enterprise?
That is the riskiest arrangement of all.
Even with no clause, invoicing the same tasks to the same principal exposes you to Reclassification as employment, which URSSAF actively looks for during an inspection.
Moving from employee to contractor means changing the assignment, not just the paperwork.
Does my exclusivity clause hold if I work part time?
Rarely.
Banning any other activity for a part-time employee amounts to denying him the means to earn a living: the clause is then justified only by the very particular nature of the task entrusted, and it must stay proportionate to that precise aim.