Receiving faxes without a machine: the virtual number

Short answer: receiving faxes without a machine relies on a virtual number — a fax number attached not to a physical line but to a service that converts the incoming call into a file and drops it into a mailbox or a secure workspace. Two decisions shape everything else: whether or not to keep your current number (porting is a right, governed in France by Article L. 44 of the Postal and Electronic Communications Code, but it takes weeks of preparation) and knowing where the documents you receive will be stored — a central question as soon as health data or material covered by professional secrecy is involved. The rest — PDF or TIFF format, notifications, receipts, archiving — is a matter of configuration. The classic mistake is cancelling the line before porting the number: it then becomes unrecoverable, and all your correspondents keep dialling a dead number for months.

Sending is easy; receiving is infrastructure

There is an asymmetry that few people anticipate. To send a fax, you need nothing permanent: an online service, a document, a destination number, and it's done. That is what our guide to sending faxes online covers. To receive, it's the opposite: you need a number that belongs to you, that rings around the clock, and a system capable of answering the fax protocol at any hour.

In other words, reception is a subscription, not a one-off use. And that is precisely the item that stalls most migrations. A dental practice, a notary's office, an HR department or a care association will all tell you the same thing: "we hardly ever send faxes any more, but we still receive them." Testing laboratories, court registries, health insurance funds, mutual insurers, local authorities, colleagues running older systems — the incoming flow long outlives the outgoing one.

Unplugging the machine without a reception solution therefore means cutting off a channel that is still being fed. The documents don't vanish into thin air: they trigger a failure tone at the sender's end, who redials, then gives up, then calls you assuming you have moved premises.

What a virtual fax number really is

A virtual number is a geographic or non-geographic number assigned by an operator, but whose termination point is not a wall socket. When a correspondent dials that number from their fax machine, the platform answers on your behalf, negotiates the T.30 protocol just as a machine would, receives the pages, and turns them into a file.

What you then receive depends on the configuration:

• an email with the document attached (the most common, the least secure);
• a drop into an online workspace protected by authentication, with a simple email notification;
• an automatic deposit into a shared folder or an electronic document management system;
• in medical environments, direct injection into the practice software through a dedicated interface.

The distinction is not cosmetic. A fax received as an attachment to an unencrypted email travels across several servers, is copied into mail backups and remains readable by anyone with access to the mailbox. For laboratory results or court documents, that is a choice that must be made knowingly and documented.

Keeping your number: porting, step by step

This is the most sensitive part of the whole operation. Your fax number appears on your prescriptions, your letterheads, your business cards, professional directories, insurance fund records and the address books of every one of your correspondents. Losing it costs far more than the subscription itself.

The principle. Porting fixed-line numbers is a customer right, overseen in France by ARCEP. The new operator — here, the virtual fax provider — submits the request to the old one. You never have to cancel anything yourself: porting automatically terminates the original line. That is the rule many people are unaware of, and that ignorance costs them the number.

What to gather before submitting the request:

The account-holder trap. If the line is in the name of a former partner, a dissolved company, a maiden name or a changed trading name, the request will be rejected. Sort it out first with the existing operator, which can take several weeks. It is the number-one reason for rejection.

The hunt-group trap. Many professionals have their fax as a "secondary line" in a hunt group alongside their main voice number. Porting the fax on its own can, depending on the setup, destabilise the whole arrangement. Get written confirmation from the operator that the line can be ported in isolation.

The lead time. Allow one to four weeks between the request and the actual switchover, longer for complex business lines. Keep the machine plugged in during that window.

The overlap period: four to six weeks you must not skip

A successful migration looks like this: for a month, both channels run in parallel. The physical line stays active, and you bring a temporary virtual number into service that you circulate gradually. You observe what actually arrives on the old number — and you often discover forgotten flows: the pension fund, a supplier, a public body sending a monthly acknowledgement.

A simple paper logbook kept next to the machine is enough for this phase: date, sender, type of document. After four weeks, you have an exact map of your incoming correspondents, and you know who to write to in order to announce the change. That inventory is also the raw material for your record of processing activities if you fall under the GDPR.

This step dovetails with the approach described in our six-step migration plan: reception is the weakest link, the one people deal with last when it should be dealt with first.

The format of incoming files: PDF, TIFF, and why it matters

An incoming fax is an image. The question is not an aesthetic one; it is legal and practical.

Multipage TIFF is the historic fax format: faithful to the received signal, with no re-compression, but heavy and poorly supported by browsers and smartphones.

Image PDF is the current standard: each page becomes an encapsulated image. Readable everywhere, fine for day-to-day archiving.

PDF with a text layer (OCR) adds character recognition on top of the image. Hugely convenient — you can find a document by searching for a name — but be careful: OCR makes mistakes, and recognised text has no greater evidential value than the image. It is a search index, not an official transcript. Never replace the original image with the recognised text.

PDF/A is the ISO 19005 standard dedicated to long-term preservation: embedded fonts, no external dependencies, guaranteed readability ten years from now. It is the format to favour as soon as a document goes into archive. The preservation principles are set out in our article on archiving faxes for ten years.

One last, often overlooked point: resolution. Standard fax works at 200 × 100 dots per inch, "fine" mode at 200 × 200. On a handwritten report or a table of results, the difference is decisive. If your platform offers the option of forcing reception in fine resolution, enable it.

Where your documents land: the GDPR question

Receiving a digitised fax means entrusting a third party with processing documents that often contain personal data, and sometimes sensitive data. Three checks are essential before signing.

1. The processing agreement. Article 28 of the GDPR requires a written contract between the controller (you) and the processor (the platform). It must set out the purpose, the retention period, the security measures and what happens to the data at the end of the contract. A provider that does not offer this document cannot be used for professional purposes.

2. Server location. Hosting within the European Union avoids international transfer issues. For health data, the bar is higher: Article L. 1111-8 of the French Public Health Code requires a certified HDS host (Health Data Host), a certification issued under the supervision of the Agence du Numérique en Santé. This is not a contractual option; it is a legal obligation. The subject is developed in our article on medical faxing and health data.

3. The provider's retention period. How long does the platform keep a copy of the document after delivery? Seven days? A year? Indefinitely? That answer must be in black and white. A service that keeps everything "for your convenience" multiplies copies of confidential documents beyond your control.

Add one simple internal rule: the inbox is not an archive. Documents are extracted from it, filed, then deleted from the mail system. For organisations that want to keep a local offline copy, an encrypted external hard drive stored in a locked drawer remains the cheapest backup — provided you test it once a year.

What if you no longer want to receive faxes at all?

That is a legitimate strategy, provided you organise it. Three approaches, in increasing order of bluntness.

Redirect with a message. You keep the number, but the platform replies with an automatic page indicating the new channel (secure email address, exchange platform, registered electronic mail). The sender receives a transmission confirmation and finds the printed message. Minimal cost, gentle transition.

Passive upkeep. You keep a low-cost virtual number without publicising it, purely to catch the correspondents who still use it. A quarterly review of what comes in tells you when you can pull the plug.

The clean cut. Reserved for organisations that have verified, log in hand, that no incoming traffic has arrived for six months. Even then, notify your institutional partners in writing: some have automated processes that nobody monitors internally any more.

In every case, update your materials. A customisable rubber stamp to temporarily correct the letterhead on your old forms saves throwing away three boxes of headed paper, and a reprint of your professional business cards closes the matter as far as correspondents are concerned. Remember professional directories, the records held by professional bodies and insurance funds, and the legal notices on your website.

What a virtual fax does not prove

A closing word of caution. Receiving a fax as a PDF does not turn the document into stronger evidence. The platform can timestamp reception, log the call, record the calling number passed through the signalling — but that calling number is self-declared and can be spoofed. The reception log establishes that a fax call was indeed received at a given time and produced a given number of pages; it does not establish the sender's identity with certainty.

If evidential stakes are real, systematically keep: the received file, the platform log, and the timestamp. The question of legal value is covered in detail in our article on the evidential value of a fax before a judge. If in doubt, a recent edition of a practical guide to the law of digital evidence is worth more than a rough search on a forum.

Frequently asked questions

Can I receive faxes on an ordinary Gmail address?

Technically yes, most services allow it. Legally, it is inadvisable for any confidential business document: consumer email offers neither a suitable processing agreement, nor any guarantee of data location, nor HDS certification. For strictly personal use — receiving a tenancy agreement or an administrative document — it is acceptable.

How long does it take to port a fax number?

Allow one to four weeks for a simple line, longer if the number belongs to a hunt group or if the account holder's identity needs to be corrected. Never cancel the original line: porting triggers the termination itself.

Can I get a fax number in another country?

Yes, most platforms offer numbers in several geographic areas, allowing your overseas correspondents to dial a local number. Check the list of available countries to confirm coverage.

What happens if two faxes arrive at the same time?

On a physical line, the second call gets an engaged tone and the sender has to redial. This is one of the concrete advantages of a virtual number: most platforms accept several simultaneous calls on the same number, with no practical limit.

Should I keep a backup machine?

Rarely useful. If the platform has an incident, the sender gets a failure notice and will call back. If your activity demands strict continuity — a laboratory, an on-call medical service — it is better to arrange a second number with another provider, set up as a conditional redirect.

Do received faxes count towards my archiving obligations?

Yes. A document received by fax has the same status as the same document received by post. Retention periods depend on the nature of the document, not the channel it arrived through: ten years for accounting records, twenty years for a medical file from the date of the last consultation.

In summary

• Fax reception is a permanent subscription, not a one-off service: it is reception, not sending, that stalls most migrations.
• Port your number rather than changing it: obtain the RIO code by dialling 3179, check that the account holder details are exact, and never cancel the original line yourself.
• Plan for four to six weeks of overlap with both channels active, and keep a log of incoming faxes to map your real correspondents.
• Favour PDF/A for archiving, always keep the original image alongside any OCR text, and force reception in fine resolution.
• Insist on an Article 28 processing agreement, European hosting, and HDS certification as soon as health data is involved.
• The inbox is not an archive: extract, file, delete.
• A received fax, even timestamped, does not prove the sender's identity: keep the file and the platform log.