Fax to the Gendarmerie: Complaints and Attachments

Short answer: you cannot file a criminal complaint by fax. A complaint is filed at the front desk of a brigade de gendarmerie (gendarmerie brigade) or a commissariat (police station), online for certain offences, or by letter to the procureur de la République (public prosecutor) of the tribunal judiciaire (civil and criminal court) — article 15-3 of the code de procédure pénale (Code of Criminal Procedure). A brigade or police station does, however, very commonly accept by fax anything attached to a case already opened: additional documents requested by an investigator, a medical certificate, an invoice or quote estimating a loss, proof of insurance, proof of identity, a reply to a summons, the appointment of a lawyer, or a response to a judicial request addressed to a professional. Golden rule: state the case file number (PV, official report) and the investigator's name at the top, address the exact unit — not "the gendarmerie" in general — and keep the transmission report, the only document able to prove the date and time of sending.

What a fax can and cannot do with a brigade

The confusion stems from a misunderstood fact: the gendarmerie and the national police do have fax machines, many still do, and those numbers circulate through judicial request channels. But having a fax does not mean everything can be received on it.

The key point: a fax does not create a case, it feeds an existing one. As soon as an official report has a number and an officer has asked for a document, the fax delivers that document the same day, with a time-stamped trace. This is exactly the use documented elsewhere on this site for courts: see does a fax carry evidentiary weight before a judge?.

What about emergencies?

Let us be blunt: no emergency should ever go by fax. Violence in progress, someone in danger, a burglary witnessed, a worrying disappearance: 17 (police/gendarmerie emergency), 112 (European emergency number), 114 (by text message for deaf and hard-of-hearing people). A fax can sit in a tray all night. For anything that is a formal but non-urgent report, the framework is detailed in reporting by fax: alerting the authorities the right way.

Filing a complaint: the three real routes

Since fax is ruled out for the filing itself, it is worth knowing the three valid routes, because they shape what follows — and it is at the "what follows" stage that fax becomes useful again.

1. Filing at the front desk. Every gendarmerie brigade and every police station is obliged to take a complaint, regardless of where the offence took place or where the complainant lives. You leave with a receipt (récépissé) stating the case file number — write it down, it is the key to every later exchange.

2. The online complaint. The ministère de l'Intérieur (Ministry of the Interior) has rolled out online filing for certain offences where the perpetrator is unidentified (fraud via the THESEE platform, property offences, discrimination via the dedicated platform). The official portals are service-public.fr and the Ministry of the Interior website; be extremely wary of paid intermediary sites.

3. The letter to the public prosecutor. This is article 15-3 of the Code of Criminal Procedure, with article 40 governing what follows: you write to the prosecutor of the court covering the place of the offence or the perpetrator's home, by registered post with acknowledgement of receipt. The complaint sets out the facts, the date, the place, the perpetrator's identity if known, the loss suffered, and encloses the supporting documents. For that letter, a pack of white 80 gsm A4 paper and a set of C4 window envelopes save you from folding documents that must stay legible when scanned.

In all three cases, the written submission must be clean, dated, signed, and accompanied by copies — never originals. A portable document scanner, flatbed or sheet-fed, makes assembling the file far more comfortable than a phone photo, whose shadows and distortions destroy legibility once faxed.

Fax after filing: where it really comes into play

This is where everything happens. Once the case is opened, the investigator needs documents, often on a tight schedule before transmission to the prosecutor's office. The most frequent requests:

• the initial medical certificate (certificat médical initial, CMI) or certificate recording assault injuries, stating the ITT (incapacité totale de travail — total incapacity for work in the criminal law sense, which determines whether the offence is a minor offence or a misdemeanour);
• invoices, quotes, photos quantifying a loss (theft, damage, accident);
• proof of address and identity document when identity must be confirmed;
• proof of insurance or a claim declaration, often cross-checked with the complaint;
• bank statements and screenshots in online fraud cases;
• a letter appointing a lawyer, or a request to be interviewed with counsel present;
• a reply to a summons: justified unavailability, request to reschedule, sick-leave certificate.

Two pieces of advice that change everything. First, write the case file number and the investigator's name at the top of the first page, in large type, not just on the cover sheet: pages get separated. Second, announce the transmission by phone — a ten-second call to the brigade confirms that the fax number is correct and that someone will check the tray. The useful cover sheet template is detailed in fax cover sheet: the template that stands as proof.

Judicial requests: fax from the professional's side

Many readers of this site discover gendarmerie fax numbers from the other end: they receive a judicial request (réquisition judiciaire) and have to answer it. A landlord, a building manager, a garage owner, a hotelier, a carrier, an employer, a shopkeeper with CCTV may be served a request under articles 60-1, 77-1-1 and 99-3 of the Code of Criminal Procedure: handing over information or documents useful to the investigation.

In that case:

1. Check the request: it bears a case file number, the identity and rank of the requesting officer, the endorsement of the prosecutor or of the judicial police officer, and a stamp. If in doubt, call the unit back using the number from the official directory, not the number written on the document — that is the basic anti-impersonation reflex.
2. Reply within the stated deadline. Refusing to reply without legitimate grounds is punishable by a fine provided for in those same articles.
3. Send only what is asked for. A request concerning one tenant does not justify sending the file for the whole building. The GDPR and the data minimisation principle still apply.
4. Keep proof of sending. The fax transmission report, with the date, time, page count and number dialled, is the document that shows you replied. A lever-arch cardboard archive box dedicated to judicial requests stops them getting lost among everyday accounting papers.

On how long to keep these reports, the full reasoning is in archiving your fax confirmations: for how long?.

Finding — and checking — the right number

This is the most common sticking point, and the riskiest. Brigades merge, brigade communities are reorganised, police stations change their catchment areas: a fax number found on a forum stands a good chance of being dead, or worse, of now belonging to a private individual.

Reliable sources:

• The government directory on service-public.fr, which publishes the official contact details of brigades and police stations, updated by the units themselves;
• the national gendarmerie website and that of the Ministry of the Interior, for specialised units;
• the letter or summons you received: this is the most reliable source, since the unit's letterhead appears on it, often with its fax number;
• this site's directory of official fax numbers, which lists the French public services still equipped.

Three costly mistakes, seen over and over:

Mixing up the brigade's fax and the company's. A transmission sent at département level may take several days to filter back down, or may never do so.

Faxing to the switchboard. The number starts ringing in an office, nobody picks up in fax mode, and the transmission fails without you knowing why.

Assuming a failed transmission counts as sent. A "failure" report proves nothing but the failure. You have to resend and keep the successful report.

The step-by-step verification method is detailed in finding the right fax number for a government office.

Preparing a transmission that arrives legible

An illegible medical certificate is useless, and a grey screenshot proves nothing. A few technical rules, because fax remains a black-and-white, low-resolution channel:

• black on white, no coloured background, no fluorescent highlighting (which comes out as solid grey and hides the text);
• font size at least 11 points, no cramped handwriting;
• one document per page, not three receipts stuck on one sheet;
• number the pages "1/7, 2/7…" so the investigator sees immediately whether a sheet is missing;
• crop and straighten photographed documents; the assemble a PDF file bundle tool lets you gather the documents in order before sending.

For photos of damage or injuries that have to be enclosed, printing them first on a monochrome laser printer gives a better result than sending straight from a colour file: you see in advance what the investigator will receive. And for fragile or damaged documents, transparent A4 punched pockets avoid adding creases to something that will be scanned several more times. The detailed settings are covered in fax illegible on arrival: preparing a PDF that goes through.

Frequently asked questions

Can you really file a complaint by fax?

No. The Code of Criminal Procedure provides for filing at the front desk, online for certain offences, or by letter to the public prosecutor. A fax sent to a brigade will not be recorded as a complaint and may be shelved administratively, sometimes without any reply. If you want a time-stamped written submission, the right route is a registered letter to the prosecutor — with the fax possibly coming as a supplement, once the case is open.

What about an incident log entry?

It can only be filed in person. An incident log entry (main courante) is not a complaint: it does not open an investigation, it records a statement in an internal register. It requires an interview with an officer, and therefore your physical presence.

I have received a summons and cannot attend on the stated date. Is a fax enough?

This is a textbook case where fax is appropriate. Write to the summoning unit, restate the case file number and the summons date, explain the reason (work travel, hospitalisation, childcare) with the supporting document enclosed, and offer alternative dates. Keep the transmission report: it proves the unavailability was notified before the date, which prevents you being treated as a no-show.

My insurer wants the complaint receipt — can I fax it to them?

Yes, and it is very common given insurers' short deadlines (often two working days for a theft). The receipt is a document issued to the complainant, who is free to use it as they wish. See reporting a claim by fax: deadlines, proof, good habits.

How do I know my fax reached the right office?

The transmission report proves that the receiving machine answered and accepted the pages — not that an investigator read them. The only way to close the loop is a confirmation phone call, noting the date, the time and the name of the person you spoke to. Kept in a spiral-bound A5 notebook used solely for the case, that timeline is worth its weight in gold if a dispute over deadlines arises later.

Is fax safer than email for these documents?

Neither more nor less: each channel has its weaknesses. Fax has the advantage of landing on equipment inside the unit and of producing a standardised transmission report; email has the advantage of volume and colour. The detailed comparison is in fax or secure messaging: which channel to choose?.

In summary

• Complaints and incident log entries: never by fax. Front desk, online filing on the official portals, or registered letter to the public prosecutor (article 15-3 of the Code of Criminal Procedure).
• Emergencies: 17, 112, or 114 by text message. A fax can sit unread for hours.
• Fax is for after the case is opened: additional documents, medical certificate stating the ITT (total incapacity for work), invoices, appointment of a lawyer, reply to a summons.
• For professionals served with a request (landlord, employer, shopkeeper, building manager), fax is the usual channel for replying to requests under articles 60-1, 77-1-1 and 99-3 of the Code of Criminal Procedure. Send only what is asked for.
• Case file number and investigator's name at the top of the first page, pages numbered, black on white.
• Check the number against an official source (service-public.fr, the letterhead of the letter received, the directory) and confirm by phone.
• Keep the transmission report: it alone will date your transmission if a deadline is ever disputed.