In brief:
- The confidential code is sent by post to the address registered on the certificate: after a move, it arrives at the old home. It is a common difficulty.
- Signing in with FranceConnect removes the need for the code, but only for a request made for yourself.
- Registration certificates in the old FNI format (123 AB 45) have no confidential code: there is nothing to find.
- cartegrise.com has had direct access to the registration system since 2009 (approval no. 9744, accreditation no. 14871) and states that processing and the provisional certificate take 12 to 24 hours after the complete file is received, with more than 1 million files processed.
A move, a few weeks of boxes, then comes the time to update the registration certificate. The form on the ANTS website fills in without difficulty until the confidential code field. Nobody remembers that code. The solution offered on screen is to request a new one, which will be posted to the address on the certificate, in other words to the old home.
The same situation affects duplicates and the sale of a car. Depending on the case, the answer is not the same: sometimes simply changing the way you sign in is enough, sometimes the file has to be handed to an approved professional. This guide starts from the real-life situation, then sets out what to do and how long to allow.
What to do, depending on your situation
| Situation | What blocks it | Solution to favour | Time to allow |
|---|---|---|---|
| Moved house, request made for yourself | The new code goes to the old address | Sign in to the ANTS with FranceConnect, no code needed | Immediate process, then the address label is sent by La Poste |
| Request for a relative (parent, spouse, child) | FranceConnect does not waive the code for someone else | Approved professional appointed by the holder | 12 to 24 hours after the complete file is received at cartegrise.com |
| Old-format FNI certificate | No code has ever existed | Go ahead without looking for a code | Depends on the procedure: new certificate for an address change |
| New code never arrived | Letter lost or details not matching the records | FranceConnect if the request is for yourself, otherwise an approved professional | Immediate with FranceConnect, 12 to 24 hours at cartegrise.com |
| Sale, the buyer is waiting | The online declaration of sale asks for the code | FranceConnect for the seller; for the buyer, change of owner through an approved professional | Immediate for the declaration with FranceConnect, 12 to 24 hours for the buyer at cartegrise.com |
| Verdict | The official route remains free when the request is for yourself and FranceConnect is available | In other cases, sending the letter adds a few days’ delay | An approved professional avoids that wait, in return for service fees |
Each row leads to a procedure explained further down. The full mechanism of the code, with a comparison of the three routes, is explained in our article on the three routes when the confidential code is missing.
Address change: the case where the code blocks most often
Changing the address is an obligation. The service-public.gouv.fr page “Changer l’adresse sur son certificat d’immatriculation” (changing the address on your registration certificate), consulted on 6 March 2026, sets a deadline of one month after the move. If the declaration is not made in time, the owner faces a class 4 fine of €135. The procedure can no longer be done at a prefecture: it goes through the internet or through an approved professional.
This is precisely where the confidential code is often missing. The help page of the government registration website requires it for an address change, and the new code is resent to the address shown on the certificate, which can be a difficulty after a move.
Three options are then available.
- FranceConnect, for the holder themselves. Signing in to the ANTS website through FranceConnect removes the request for the code. This is the free and immediate solution, provided you are the holder of the registration certificate and have an account with an identity provider, such as impots.gouv.fr or Ameli. cartegrise.com explains how this works on its page on FranceConnect and vehicle registration.
- A new code, if the old home is still accessible. If the letter can still be collected, for example from a neighbour or a landlord, requesting a new code remains an option.
- An approved professional. They handle the address change without the code, thanks to their direct access to the vehicle registration system.
On the official route, an address change is free for up to three declarations per certificate: a sticker is sent by La Poste, to be stuck on the registration certificate. On the fourth change, or for an old-format certificate, a new certificate is issued for €2.76. At cartegrise.com, the service fee for an address change is €44.90.
For details of the documents to provide and the penalties, the guide to the registration address change and its legal deadline takes you through the procedure step by step.
Duplicate and sale: the two other procedures concerned
The duplicate
A lost, stolen or damaged registration certificate is replaced with a duplicate. On the ANTS website, this request also asks for the confidential code, unless you sign in with FranceConnect for your own car. The difficulty is common: the letter containing the code was often kept with the registration certificate, and it disappeared along with it.
If the request concerns a relative’s vehicle, or if the FranceConnect account is not available, an approved professional remains the solution that does not depend on a letter. At cartegrise.com, the service fee for a duplicate is €54.90, on top of the taxes, which are the same as on the official route: an €11 management tax and a €2.76 delivery fee.
The sale
Selling a car means declaring the sale. The service-public.gouv.fr page “Vendre ou donner son véhicule” (selling or giving away your vehicle) describes the online procedure: registration plate, mobile phone number, then the confidential code received with the registration certificate. A seller making the request for themselves can sign in with FranceConnect and avoid this code.
One point deserves attention. According to the same page, a seller who hands the declaration of sale to an approved professional must give them the confidential code, for security reasons. For a sale, FranceConnect therefore remains the direct route on the seller’s side.
On the buyer’s side, the situation is different: the change of owner can be handed to an approved professional. cartegrise.com requires neither a transfer code nor a confidential code, and charges €44.90 to €99.90 for this change of owner depending on the amount of the regional tax. The declaration of sale alone costs €34.90 there. To secure the transaction from start to finish, the checklist for buying a used car lists the documents to ask the seller for.
Preparing your request so you do not have to start again
A few checks before signing in avoid getting stuck halfway.
- Look at the registration number format. A plate in the 123 AB 45 format corresponds to an FNI certificate, with no confidential code. A plate in the AB-123-CD format corresponds to the current system: the code exists and appears on the letter received with the registration certificate.
- Look for the cover letter. The code is printed in bold, in the middle of the letter. It often turns up in the vehicle papers wallet or in the purchase file.
- Compare the address on the certificate with the current address. If they differ, requesting a new code means sending it elsewhere. It is better to go straight to FranceConnect or an approved professional.
- Identify the holder. If the registration certificate is in another person’s name, even a member of the household, FranceConnect will not be enough.
- Check the identity details. A date of birth recorded incorrectly on file is enough to make the request for a new code fail. The details entered must match those on the registration certificate exactly.
- Gather the supporting documents. Proof of identity, documents specific to the procedure and, for a sale, the certificate of sale: a complete file from the start avoids a follow-up request.
Once the procedure is done, one simple habit avoids going through this again: keep the cover letter that comes with the new registration certificate, or write the code down somewhere safe. For anyone planning to hand future procedures to a provider, the guide to online vehicle registration explains how approved professionals work.
At cartegrise.com, a private provider separate from the ANTS, the process uses a standard account (email and password), the file is checked before it is recorded and can be tracked in the customer area 24 hours a day, 7 days a week. The site’s page on how to register your vehicle without the confidential code details the procedures concerned. Payment in 3 or 4 instalments is available for purchases between €150 and €500.
Frequently asked questions
How do you update your registration certificate after moving without the confidential code?
A holder making the request for themselves signs in to the ANTS website with FranceConnect, and the code is not requested. Without FranceConnect, the new code is posted to the old address, which can complicate the procedure. An approved professional handles the address change without the code, for €44.90 in service fees at cartegrise.com. The legal deadline for declaring the new address is one month.
Where is the new confidential code sent?
It is sent by post to the address shown on the registration certificate. For a request made for yourself, service-public.gouv.fr states that it is also sent by email, within 24 hours at most. For a request made on behalf of someone else, only the post is used.
Can you complete the process for a relative without the code?
Not on the official website: the exemption granted by FranceConnect only covers requests made for yourself. An approved professional, appointed by the holder, handles an address change or a duplicate without this code. At cartegrise.com, processing and the provisional certificate take 12 to 24 hours after the complete file is received.
Does an FNI registration certificate have a confidential code?
No. Certificates in the old format, with a registration number such as 123 AB 45, never received one. For an address change, a new certificate in the current format is issued, for a delivery fee of €2.76 on the official route.
How long does a procedure handled by an approved professional take?
At cartegrise.com, the file is processed and the provisional certificate emailed 12 to 24 hours after the complete file is received. The final registration certificate arrives around 2 to 3 days after the provisional certificate. Some procedures can take up to 8 working days.
Further reading
How the code works, FNI certificates and the detailed comparison of the three routes are covered in our article Registration confidential code: find it or do without.
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