A SIRET number is the 14-digit ID that proves you run an official, registered business in France. You only get one when you register your business, and once you have it, it goes on your invoices, your website and your contracts.
You might be asking yourself the same thing. Or you may already have a SIRET number and not be quite sure what to do with it. Below, we look at what SIRET and SIREN numbers are, where you get them, when you use them, and whether your number can change in the future.
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1. What is a SIRET number?
A SIRET number is a unique 14-digit number that identifies your business in France. It is issued by INSEE, the French national statistics office. You don't choose it: INSEE creates it for you when your business is registered.
You will also hear about the SIREN number. This is the first 9 digits of your SIRET, and it identifies the business itself. The last 5 digits identify a specific location (an "établissement").
So if a business has several sites, the SIREN stays the same and only the last 5 digits change. Say I have an office in Paris and another in Marseille:
| Number | Digits | Paris office | Marseille office |
|---|---|---|---|
| SIREN identifies the business |
9 | 123 456 789 | 123 456 789 |
| SIRET identifies the location |
14 | 123 456 789 00013 | 123 456 789 00019 |
The last 5 digits usually start with 000, followed by two numbers.
2. Where do you get a SIRET number?
You get a SIRET number by registering a business in France. There is no other way to get one.
Registration is done online with INPI, the central hub where all French businesses are registered. You fill in the forms, describe your activity, choose your business structure (sole proprietor or company) and give your personal details.
Once your registration goes through, you receive your official business papers:
- The synthèse validée from INPI: a validated summary confirming your business is registered. Your 14-digit SIRET number appears on it.
- The Avis INSEE: an official certificate from INSEE confirming your business is registered and listed on the national business register (Registre National des Entreprises). You get this if you run a profession libérale, an intellectual or service-based activity. You can download a fresh copy from INSEE whenever you need one.
- The extrait Kbis: your official business papers if you are registered with the Chambre de Métiers (crafts and manual trades) or the Chambre de Commerce (buying to resell, food, accommodation). It is sent by the greffe du tribunal in the last email you receive when your registration is finalised.
In short, getting a SIRET number means registering a business.
3. Why are suppliers asking for my SIRET number?
French suppliers often use the SIRET number as a filter. They don't want to spend time preparing quotes for people who may never become a real customer, so they check you are a registered business first.
This can make things tricky when you are still at the project stage and just trying to get quotes to work out your costs. If one supplier won't quote without a SIRET, try others: some will be more flexible.
If your business is registered abroad and a French partner asks for your SIRET, offer them official proof of your registration in your home country instead.
4. When do you need your SIRET number?
Once you are registered, don't hide your SIRET number: it is what shows people you are an official business. You will need it:
- On all your quotes and invoices, so clients can see you are a registered business.
- On your website, in your legal notices (mentions légales). In France, businesses are expected to be easy to identify.
- In your contracts with partners or customers, alongside your business details.
- When suppliers write a quote or invoice for you.
- When you open a French business bank account. The bank will also ask for your Avis INSEE or extrait Kbis.
- When you renew your visa. About nine months after arriving, as you prepare your one-year renewal, you must prove your business is still active. Download an up-to-date Avis INSEE showing your business is active on that date. You can find it on societe.com or on the INSEE website by searching your name or SIRET number.
Why you shouldn't hide your business details
When you register, you can ask for your business details to be hidden from public directories. I don't recommend it. If your details are hidden, you can't find your certificate through these public searches when you need it. You can still get it from INSEE, but that requires an electronic signature, which is hard for many expats to get.
If you work from home and don't want your personal address on your business papers, set up a business address (adresse de domiciliation) before you register. Your business will then be listed at that address, and your personal details stay private. This is worth doing if you work as a coach or therapist, for example.
5. Can your SIRET number change?
Yes, and most people don't know this. Your SIRET number can change if you move your business to a new address.
If you move
Say you are based in Nantes and move to Strasbourg. You must update your business details on INPI with your new address. That information is then passed to the tax office and to URSSAF. You also need to tell your health insurance body so your cover moves with you.
When you move like this, your SIRET number is very likely to change: the last 5 digits identify your location. Once you have your new number, update it everywhere:
- your quotes and invoices
- your website's legal notices
- your contracts
- your URSSAF turnover declarations and income tax returns
Always use the latest SIRET number when you declare, so your turnover is allocated to your current business. The old SIRET is treated as closed.
If you close and later restart
If you close a sole-proprietor business (entreprise individuelle or micro-entrepreneur) and start a new one a few years later, don't be surprised if you get the same number back.
For example, say you registered as a coach in 2022 and closed after three years. This year you decide to teach yoga, and you still live in the same place. Your old SIRET number will simply be reactivated with the new activity description.
6. Need help registering your business?
If you want help registering your business, especially as a micro-entrepreneur, I can take care of the whole process for you. I collect your details, check your activity is described correctly, make sure you've chosen the right tax options and handle the registration until you receive your business papers. You'll also get a series of emails explaining what to do with the key documents you receive first.
➡️ Find out more about my Micro Entrepreneur registration services
