What registration involves, what an invoice must carry, and why this point decides which clients you can reach.
Why it is necessary
Three reasons, and the third is the most concrete.
A company can only pay what it can book: with no valid document, your invoice does not enter its circuit, whatever your talent.
Agencies and large accounts check this point before even looking at your work.
And a regular activity no longer fits the occasional framework: beyond a certain level and a certain repetition, registration becomes compulsory. The applicable threshold and the moment of switching are checked with an accountant.
How it works concretely
Four elements, and they fit on one page.
An activity code matching what you actually do.
A tax regime, often simplified for small turnovers, with a rate applied to a flat-rate base rather than to your real expenses.
A social affiliation, generating contributions calculated on your income.
And an electronic invoicing obligation in most cases.
What the invoice must contain
Six elements, and missing a single one is enough to block payment.
Your full details and your registration number.
The client's, including the recipient code or certified address they use to receive invoices.
An invoice number, in a continuous series with no gap.
The date, the precise description of the service, and the period concerned.
The amount, with the regime applied and, where relevant, the withholding.
And the bank details, on the document itself.
Mistakes to avoid
Waiting for the first client to open it
Opening takes time, and a client having to wait three weeks orders elsewhere. Prepare the file before needing it, even if you only activate it when useful.
Working out your income on the gross
What you take in is not what you keep. Between tax and contributions, a significant share goes back out, and it must be set aside at every payment, not at the end of the year.
Forgetting the contributions
They surprise people the most, because they are not proportional to profit but based on declared income, and they arrive on a fixed schedule.
Staying alone
An accountant costs a modest sum compared with what a wrong regime or a missed deadline really costs. Take one before opening, not after the first problem.
What is set up before the first invoice
| Step | What it unlocks | When |
|---|---|---|
| Opening the number | The right to invoice | Before the first order |
| Electronic invoicing | Compliant issuance | The same month |
| A dedicated account | Readable bookkeeping | Immediately |
What is kept, and how
The invoices issued, their electronic version, the proofs of payment and the contracts, in one folder per quarter. Filing as you go saves a week of searching.
What to ask a professional
The applicable regime, the contributions, the deadlines, the treatment of foreign clients and the threshold for changing regime, to be confirmed with an accountant.
What it changes for your clients
Two immediate consequences, visible from the first month.
You become eligible for structured brands, agencies and tenders, which represent most of the available budget.
And you can invoice long usage rights, which is impossible without a framework: a written assignment presupposes an identifiable issuer, and that is exactly what registration provides.
Sources
Checked on 26 August 2026. Thresholds and rates change: where this guide and the official source disagree, the official source is right.
