How to verify the authenticity of a document

Is this a fake document? Three separate questions

Asking whether a document is real hides three different questions. Is it authentic, meaning issued by whoever it names? Is it intact, or has it changed since it was issued? Is it accurate and current, meaning true at the moment you check it?

A document can pass one test and fail another. A French tax notice may be untouched yet no longer the latest one: the tax authority’s checking service (in French) answers exactly that, and a “non-compliant” result can simply mean that a newer notice exists. Conversely, a genuine document re-saved by the person who received it may show unusual file properties while hiding nothing.

No single check answers all three questions. The method below combines them, from the simplest to the most technical, and it applies to almost anything: an invoice, a certificate, a diploma, a contract. Registers and services differ from one country to another, but the logic does not.

The 4-level method

1. Trace it back to the issuer

   Does the organization exist, and can it confirm this document? Look it up in an official register and contact it through details you found yourself: those printed on a doubtful document may be fake too.

2. Test the content for consistency

   Dates, amounts, identifiers and names must hold together, within the document and against the rest of the case file. Redo the sums, compare the documents with one another, and ask whether this really looks like what it claims to be.

3. Examine the file

   A digital file is more than a picture of a page: it holds properties and sometimes several saved versions. Ask for the original rather than a screenshot, then read that information, for example with our free tool, which runs in your browser and sends nothing anywhere.

4. Check codes and electronic signatures

   A signed barcode, a digital signature or a verification code gives you something firmer than appearance, provided you use the right tool and compare the result with what is printed.

Then conclude on the whole picture: one isolated clue justifies a question, not an accusation. Short on time? Start with level 4 when a code is present, then level 1, since those two rely on a source outside the document.

Issuer and content: official services worth knowing

Official services let you cross-check a document or its issuer. Start with the national business register of the country concerned, then look for services like these:

• An EU VAT number: the VIES tool shows whether a business is registered to trade across borders in the EU. An invalid result is not proof of fraud: the number may just not be activated for intra-EU transactions.
• An identity or travel document: the European public register PRADO lists authentic documents, useful as a point of comparison.
• A French company: the national statistics office’s Sirene status notice confirms its registration, and Infogreffe’s check confirms a Kbis extract using its verification code.
• A French tax notice: the checking service takes the tax number and the notice reference, and confirms whether it is the latest notice known to the authorities.
• A French diploma: diplome.gouv.fr now points to the Cyclades platform for diploma certificates.

For the content, look for whatever ought to agree. On an invoice, the net amount, the VAT and the total add up, and the VAT number belongs to the company. On a payslip, the net pay is consistent with the transfers on the bank statement. Across a whole case file, a name is spelled the same way everywhere, and an address does not change from one document to the next without a reason.

An inconsistency is not necessarily fraud: a typing error or a recent change of situation can explain it. It simply tells you where to ask the next question.

How to spot a fake PDF

A PDF can hold readable properties: creation and modification dates, the original application, the software that produced the PDF. The ISO 32000 standard also lets a file be updated by appending changes while leaving its earlier content intact, so one PDF can carry several states. Three questions help you read all this:

• Are the dates plausible? A change made long after the stated issue date deserves a question.
• Does the origin fit the issuer? A statement generated by a bank’s system should not look like a file that came out of an image editor.
• Does the file keep earlier versions? They may show what changed, or merely an added signature or a completed form.

These properties are clues, not proof. The standard makes most of them optional, and Adobe points out that an author can edit or remove them. A file with no properties, or a re-saved one, is not fake for that reason, and spotless properties do not make a document authentic.

On a scan or a photo, this information describes the device rather than the original document. Look at the rendering instead: an area sharper or blurrier than the rest, a different background around some text, an alignment that drifts. Images created entirely by a machine raise a separate question, covered in our guide to AI-generated documents.

Codes and electronic signatures: what they guarantee

Signed barcodes. Some countries print a signed barcode on everyday documents. In France, France Titres (page in French, read on 2 November 2026) reports its 2D-Doc code on more than 50 types of document, including proofs of address, tax notices and payslips. You read it with a recognized app, then compare it with the page. A valid signature vouches for the data in the code and for nothing else. Our 2D-Doc guide explains how.

Digital signatures on a PDF. Software such as Acrobat runs two separate checks: the signer’s identity and the document’s integrity. They are not the same thing: a document may be intact while your software does not recognize the signer. Legally, within the EU, only a qualified signature explicitly has the effect of a handwritten one, while the other levels remain admissible as evidence.

To find out whether a signature is qualified, the European Commission offers a demonstration app. It is meant for testing only and files are sent to its servers, so do not upload anything sensitive.

Pictures of signatures. A signature or stamp placed on the page cannot be verified: only a digital signature based on a certificate lets you check the file’s integrity.

Checking each type of document

Each document has its own weak points. Our dedicated pages cover the method, common frauds and official checks, with a focus on French documents:

• Income and finances: payslip, tax notice, bank statement.
• Address and company: proof of address, Kbis extract.
• Invoices and spending: invoice, expense report.
• Health: sick leave certificate, medical prescription, medical fee note.
• Insurance: insurance claim photo.
• Education: diploma.

Some documents come with rules of their own. In France, since 1 September 2025, the paper sick note has been a secure form (in French), and health insurers reject scans and photocopies of it. When a document is part of a set, check the set as well: our guide to the fake rental application shows how.

Mistakes to avoid

• Trusting appearance. A polished layout proves nothing, and neither does a clumsy one: small genuine organizations issue modest-looking documents.
• Treating an anomaly as fraud. A re-saved file, a different font or an empty field can have a mundane cause.
• Reading a code without comparing. A valid signature is worthless if nobody compares the data shown with the document in front of them.
• Calling the number printed on the document. Verify the issuer through a source you found yourself.
• Accepting a screenshot when an original file exists. You lose the information held in the file.
• Accusing too soon. Ask for an explanation or another document first, and keep a record of what you verified.

If forgery is established, legal consequences may follow. In France, article 441-1 of the Criminal Code (in French) punishes forgery and the use of forged documents with three years in prison and a €45,000 fine. What to do next is for your legal department, and our guide on document fraud says more.

Automating the file check

Tracing an issuer and cross-checking a case file take knowledge of the context. Examining the file itself takes time and tools, and the eye does not catch everything. Docusan, a French document fraud detection service, analyzes the file you receive, in PDF, PNG, JPEG or TIFF format, and gives a verdict: No detection, Warning or Alert. The anomalies are located on the document, and the decision always stays with your teams.

Docusan does not contact the issuer or government databases: it complements the checks above and does not replace them. You can use it from the platform or integrate it into your tools with its API, available with the Enterprise plan. Hosted in the European Union, your documents are never used to train or improve our models (security and privacy). To compare options, see our guide to choosing detection software.