The most frequent error on the Guichet Unique: signing a formality with an advanced signature, believing it's enough, and seeing the PDF rejected with a generic message "Signature non conforme" or "Niveau de signature insuffisant" (Insufficient signature level). This article explains precisely why and how to fix it in minutes.

The misunderstanding: advanced is not qualified

The European eIDAS Regulation 910/2014 defines 3 levels of electronic signature, hierarchised by their legal force:

The trap: advanced signature has all the visual markers of qualified. It's secure, verifiable, tamper-proof. But it doesn't have the official European label requiring an ANSSI audit and specific infrastructure. For most commercial contracts, advanced is enough. Not for INPI.

Why does INPI require qualified, not advanced?

The Guichet Unique modifies the French commercial register, which has legal publicity value. A fake signature on a business cessation or director change can have serious consequences:

INPI therefore aligned on the highest European standard: a certificate audited by ANSSI, based on a strict PVID identity verification (front/back photo of an official ID + selfie + SMS code), with a certified journey.

The Guichet Unique cryptographically verifies on PDF reading:

If even ONE check fails, automatic rejection.

To remember A well-designed advanced signature can be technically more secure than a poorly-designed qualified signature. But INPI doesn't judge real security: it checks the official label on the EU Trust List. It's administrative, not technical.

Providers producing advanced (rejected by INPI)

Here are the solutions sometimes wrongly proposed as sufficient for INPI:

Yousign Pro (basic plan)

Basic Yousign Pro produces advanced signatures. To get qualified level, you must move to Yousign Pro+ (with €5 to €12 surcharge per qualified signature). See pricing comparison.

DocuSign Standard

DocuSign Standard at €38 ex. VAT/month produces simple or advanced signatures. Qualified requires upgrading to DocuSign Business Pro (€52 ex. VAT/month) with limited quota.

Adobe Sign / Adobe Acrobat

Adobe Sign mainly produces simple signatures. The "Adobe Approved Trust List" feature allows advanced, but not qualified in the strict eIDAS sense.

Some real estate or commercial management platforms

Many tools integrate "secure" advanced-level signatures. Sufficient for a lease or commercial contract, but insufficient for INPI.

How to know if your signature is advanced or qualified?

3 verification methods:

1. Open the PDF in Adobe Reader and read signature properties

Right-click the signature → "Signature properties" → "Validate" tab. Adobe shows the eIDAS level of the certificate. If you see "Qualified Electronic Signature (QES)" or "Qualified level", it's good. If you see "Advanced Electronic Signature (AdES)", it will be rejected by INPI.

2. Verify the issuer on the EU Trust List

Go to eidas.ec.europa.eu/efda/tl-browser, select "France", search the provider name appearing in signature details. If it's not listed as "QSCD" or "QC for eSignature", the signature is advanced only.

3. Ask the provider explicitly

At payment, ask: "Is the applied signature level qualified within eIDAS, with certificate issued by a provider listed on the EU Trust List?" The answer must be yes without ambiguity. Any evasive wording ("certified", "secure", "approved") is suspicious.

How to switch to qualified quickly?

Good news: your original PDF summary downloaded from the Guichet Unique is still usable. You just need to re-sign it correctly.

Step 1 — Re-download the summary from INPI

Reconnect on procedures.inpi.fr, find your formality (status "Awaiting signature"), re-download the original PDF.

Step 2 — Sign with a qualified provider

Drop the PDF on SignerSynthèse.fr or another provider listed on the EU Trust List. The journey takes 2 to 5 minutes: upload, identification, payment (€29 ex. VAT), PVID identity verification, qualified signature applied.

Step 3 — Upload the qualified-signed PDF back

Go back to the Guichet Unique, upload the new qualified-signed PDF. This time, cryptographic verification passes and the formality is validated instantly.

Advanced signature rejected? Switch to qualified in 2 minutes.

eIDAS qualified signature via Universign (EU Trust List). €29 ex. VAT, delivered by email, 100% accepted by the INPI Guichet Unique.

Sign my summary →

FAQ: advanced signature and INPI

Is an advanced signature legally valid?

Yes, in private and commercial contracts. It has probative value in case of dispute (Article 1366 of the French Civil Code). But INPI specifically requires the qualified level for sensitive company formalities.

Why doesn't INPI accept advanced level?

Because the consequences of fraud on the commercial register are heavy: false director change, false cessation, false capital modification. Qualified guarantees the signer was physically identified, which advanced doesn't always guarantee.

Can my current provider "upgrade" my advanced signature to qualified?

No. The signature is immutable once applied. You must re-sign the original PDF with a qualified provider. Don't waste time asking for an upgrade; go directly to re-signing.

How much does the advanced-to-qualified switch cost?

Pay-as-you-go qualified signature costs €29 ex. VAT at SignerSynthèse.fr. You only pay for the qualified signature itself; there's no surcharge for having tried advanced first.

How much time is wasted by starting over?

5 minutes. The original PDF summary is still available on the Guichet Unique as long as the formality is not validated. No re-entry of formality information.

Conclusion

The advanced signature is an excellent level for most business uses. But for the INPI Guichet Unique, it's insufficient: only the qualified eIDAS level with certificate from a provider listed on the EU Trust List passes automatic verification. If your advanced signature was rejected, don't waste time understanding the technical cause: re-sign in qualified, it's a 5-minute matter.

Official sources