Definition
You teach, you nurse in a hospital or you work for a town hall, and an organisation offers you a Saturday training session.
The instinct is to register a micro-enterprise in ten minutes, then mention it later.
French law works the other way round: a public agent owes the whole of their professional activity to their post, and running a private business for profit is forbidden as a matter of principle.
Combining the two does exist, but as an exception, organised by the chapter of the code général de la fonction publique (general civil service code) devoted to the rules on combining activities.
The rule covers established civil servants and public-law contract staff alike, across the three branches of the French public service. It does not say "no", it says "ask first".
Registering your Micro-enterprise before your line management has agreed puts you at fault over an activity that would very often have been waved through.
This has nothing to do with Combining with employment in the private sector, where only the employment contract has a say.
Free, declared, authorised: the three doors
Everything depends on which door your project goes through, and they do not ask the same of you.
The first is freedom. Producing works of the mind, writing a book, publishing articles, composing music, needs no permission, subject to professional secrecy and to your ethical obligations.
The second is a declaration.
An agent on a part-time or incomplete post, whose working share stays below the level set by the regulations, simply informs their employer in writing and has no authorisation to obtain.
The third is prior authorisation, and it covers most projects.
The accessory activities on offer form a closed list set by decree, and few of its entries lead to a micro-enterprise: expert work and consultancy, teaching and training, sports or cultural coaching, personal services, selling goods you make yourself, minor work for private individuals, farming.
The request sets out the client, the nature of the activity and how long it will last, and silence from the administration counts as a refusal.
You will read everywhere that a civil servant can only be a micro-entrepreneur for personal services and for selling self-made goods.
The truth is the opposite, and the decree says so in as many words: for those two, the micro regime is compulsory, while most of the other activities on the list may use it without being obliged to.
Consultancy or training therefore sits perfectly well inside a micro-enterprise, once the authorisation is in hand.
The calculation, on round numbers
A local-government officer authorised to run training sessions collects 6,000 € in 2026.
The activity is a non-regulated liberal one: it falls under BNC (bénéfices non commerciaux, non-commercial profits) and under the general scheme, not under Cipav.
Her Social contributions come to 25.6% of revenue in 2026 for that category, which is 1,536 €.
On top of that sits the CFP (contribution à la formation professionnelle, vocational training levy), 0.2% of revenue in 2026 for liberal professions, so 12 €, due because she already declared positive revenue in the previous calendar year.
She therefore pays 1,548 € to URSSAF and keeps 4,452 €.
Income tax is worked out elsewhere, and it is not covered by that 25.6%.
The BNC Standard allowance is 34% in 2026: 6,000 minus 2,040 leaves 3,960 € of taxable profit, which joins her salary on the household's income tax return.
That top-up is not taxed on its own, it lands on top of the salary, so at the rate of your highest bracket.
Then there is what those 1,536 € actually buy.
No calendar year can validate more than four pension quarters, and a full-time agent already has them through their public post: the contributions paid here build extra entitlements, never extra quarters.
Salary and revenue: clearing up the confusion
The 6,000 € collected are never income. Turnover is what lands in the account, income is what survives contributions and tax.
An agent who thinks the way a payslip thinks, where the net figure is already net, will be out by half on what those Saturdays actually pay.
Two corrections follow.
ACRE is not a welcome gift.
Since 1 January 2026 it requires belonging to one of the categories listed in article L5141-1 of the labour code, or trading in a zone France ruralités revitalisation, ZFRR or ZFRR+.
Those are the French rural revitalisation areas. And it has to be claimed from URSSAF within 60 days of the start date declared at the guichet unique, the one-stop shop.
Holding a public post does not put an agent in any of those categories by itself.
Then the CFE (cotisation foncière des entreprises, business property tax).
Nothing is due for the year of creation, but the two-to-three-year relief still credited to auto-entrepreneurs was repealed by the 2014 finance act.
And working from home with no dedicated premises exempts you from nothing: the minimum charge still applies, on a base set by your local authority according to your revenue band.
There is one way out for a modest side activity: in 2026, revenue of 5,000 € or less over the reference period, the year before last or failing that the previous year, removes that minimum charge.
Frequently asked questions
Do you have to go part-time to get started?
For an authorised accessory activity, no: it is carried out outside service hours, on a full-time post.
For creating or taking over a business, on the other hand, moving to part-time is the very condition of the authorisation, which is granted for a limited period and can then be renewed on a request filed before it runs out.
What does an agent risk by not asking for authorisation?
Combining activities without permission exposes you to repaying the sums received, recovered directly from your salary, and to a disciplinary sanction.
The authorisation can also be withdrawn along the way if the activity ends up disrupting the service or creating a conflict of interest with the duties you perform.
Does the salary count towards the micro-enterprise ceiling?
No: the ceiling looks only at revenue collected, 83,600 € for services as well as for liberal activities over the years 2026 to 2028.
The salary does count, however, towards the reference tax income that governs the flat-rate income tax option, whose 2.2% BNC rate covers income tax alone and requires a reference tax income for the year before last at or below 29,315 € per household share for 2026.