Qualified certificate
and INPI signature: what the Guichet unique really requires
In short
The Guichet unique displays: It is an advanced signature based on a qualified certificate.
In practice, when you upload, it checks the authority that issued the certificate, the validity of the chain, and that the signature belongs to a person. Sign your summary document here in a few minutes, from €19.90 incl. VAT.
You are at the last step of your formality, the “Sign” button is in front of you, and the message stops you. This page explains, without jargon, what the Guichet unique, what it actually checks when you upload your document, and the three ways to get a signature it accepts.
1. The exact message of the Guichet unique
On the “Signature” screen of an amendment, a closure, a deed filing or an annual accounts filing, the INPI Guichet unique displays:
The law sets the level of signature required by the Guichet Unique for amendments, closures, deed filings and account filings. It is an advanced signature based on a qualified certificate.
Two words matter in that sentence: “advanced” (the level of the signature) and “certificate” (what proves who is signing). They do not mean the same thing.
2. Three terms, three different things
The European eIDAS regulation (EU Regulation 910/2014, Article 3) defines three levels of electronic signature and one type of certificate. Here is what each one changes for you.
| The term | What it is | What it changes for your filing |
|---|---|---|
| Simple electronic signature | A typed name, a pasted signature image, a “Signed with” stamp from office software | Rejected by the Guichet unique for these filings |
| Advanced electronic signature | A signature linked to you alone, which detects any later change to the document, created with a certificate in your name | This is the level asked for by the Guichet unique |
qualified certificate for electronic signature(eIDAS, Art. 3) | The certificate that attests your identity, issued by an authority on the European Union trusted list | This is the certificate the advanced signature must be based on |
qualified electronic signature(eIDAS, Art. 3) | An advanced signature created with a secure device in addition to the certificate; it is equivalent to a handwritten signature across the Union | This is not what the Guichet unique message asks for: it refers to an advanced signature |
In short: the Guichet unique asks for an advanced signature, based on a certificate issued by an authority on the trusted list of the European Union. Many pages sum this up with a shortcut that mixes the two: that is the first source of confusion.
3. What the Guichet unique checks when you upload the signed document
What we observe at filing, time after time: the Guichet unique checks three things when the signed document is uploaded.
- The certificate chain is valid. The certificate is not expired or revoked, and its chain leads back to the authority that issued it.
- The authority is on the European Union trusted list (the list published by the Commission, where each Member State registers its trust service providers).
- The signature belongs to a natural person. An electronic seal in a company’s name, even if perfectly valid, is rejected (Article R123‑5 of the French Commercial Code: the filing is signed by the filer).
That is why a signature made with office software, even one “validated” by that software, is rejected: the authority is not on the list. Our commitments page details what your signed document contains.
4. The three ways to get an accepted signature
| Solution | How it works | What it costs |
|---|---|---|
| FranceConnect+ with La Poste’s Identité Numérique | You log in with your digital identity and the Guichet unique signs for you (when the login does not work) | Free |
| A personal certificate bought from a trust service provider | You receive a certificate in your name after an identity check, then sign yourself for 1 to 3 years | €59 excl. VAT per year (public price noted in 2026) or €149 excl. VAT for 3 years at Namirial (price page noted in 2026) |
| A pay-per-signature service such as ClairSign | You upload your summary document, sign it, and receive the signed document by email in minutes | from €19.90 incl. VAT, paid once, shown before any payment |
In all three cases, the result is an advanced electronic signature, based on a certificate issued by an authority on the European Union trusted list: the format the Guichet unique expects.
5. The most common rejections, and their cause
| What you see | The cause | What to do |
|---|---|---|
Your signature is not valid | Simple signature, or a certificate from an authority outside the trusted list | Sign again with one of the three solutions above |
The signature contains no certification authority recognised under eIDAS. | The authority that issued the certificate is not on the European trusted list | Change signature method |
| Rejection of a document signed by the company | Electronic seal (legal entity) instead of a person’s signature | Sign in your own name, not the company’s |
| Rejection of a correctly signed document | The PDF was saved again, “printed to PDF” or edited after signing | Upload the signed document as is |
| Rejection after downloading the summary again | The summary was generated again: it is a different document | Sign the latest version you downloaded |
The messages in detail: “Your signature is not valid” on INPI: the causes and the solution.
6. Frequently asked questions
Do I need to buy a certificate to sign a single filing?
No. A personal certificate makes sense if you sign often. For a one‑off filing, FranceConnect+ (free, if the login works) or a pay-per-signature service is enough.
The message mentions a qualified certificate
: should I ask for a higher level of signature?
The message asks for an advanced signature based on a certificate from the trusted list. That is the level the Guichet unique checks at filing (part 3).
Can my accountant sign for me?
The summary document is signed by the filer. A representative can submit the filing, but the signature must be that of an authorised natural person, not a firm’s seal.
What happens if I reopen the signed document before uploading it?
Opening it to read it changes nothing. Saving it, printing it to PDF or compressing it breaks the signature: upload the file you received, as is.
How long does the signature remain valid?
The signature on your document remains verifiable after the certificate expires: what matters is that it was valid at the time of signing.
What about a public contract?
Public procurement has its own rule, written in the order of 22 March 2019: it differs from the Guichet unique’s. The details: electronic signature of a public contract.
Sign your summary document now
Upload the PDF downloaded at the “Signature” step of the Guichet unique, sign it, and receive it by email in minutes. From €19.90 incl. VAT, shown before any payment, no account needed.
Sign my documentSources: “Signature” screen of the INPI Guichet unique (2026) , Regulation (EU) No 910/2014 “eIDAS”, Article 3 , French Commercial Code, Article R123‑5 , Namirial price page, noted in 2026.