L'équipe Texto SMS Gratuit
10 October 2026 · 12 min read
Introduction: the number you don't want to lose, but don't want to pay for either
There's a whole category of mobile lines nobody talks about: the ones that are barely used, yet can't be cancelled.
The number you gave your bank back in 2009, which today receives the verification codes for your online payments. The one printed on 400 business cards. The one known to three cousins, two former colleagues and the vet. The one still listed on a holiday rental ad. The one on the phone left at your parents' place "just in case".
For these lines, actual usage amounts to a few dozen SMS received per year and two or three outgoing calls. And yet most people keep paying €10, €15 or €20 a month — €120 to €240 a year — for a service they use 2% of.
The alternative exists and it's no secret: a prepaid SIM, or a bare-bones €2 plan. But it's riddled with traps. Prepaid credit comes with a validity period. A line with no activity ends up terminated automatically. And a cancelled mobile number isn't handed back to its former holder: it returns to the operator's pool and will be reassigned to someone else after a quarantine period.
This guide explains how to keep a number alive for the price of a coffee every three months — and above all, how to avoid losing it through sheer carelessness.
Why a mobile number doesn't belong to you
This is the starting point, and it's counter-intuitive.
In France, phone numbers are a public resource. Arcep (the regulatory authority for electronic communications, postal services and press distribution) allocates them in blocks to operators, which then assign them to their subscribers. The framework is set out in the French Postal and Electronic Communications Code and in Arcep's numbering plan.
The practical consequence: you hold a right of use over your 06 or 07 number, not a right of ownership. That right of use is tied to the existence of an active contract with an operator. No contract, no number.
Three corollaries worth keeping in mind:
- There is no way to "put a number on hold" without an active line. No French operator offers a number-safekeeping service.
- Porting requires a line that is still active. To transfer your number to another operator, you need a RIO (operator identity statement), obtained by calling 3179 from the line in question. A terminated line no longer produces a usable RIO, and the grace period after termination is very short — a few days in practice, and some operators simply refuse outright.
- A released number goes back into the common pool. Arcep requires operators to observe a "quarantine" period before reassignment, so that a new holder doesn't start receiving calls intended for the previous one. But that period is a matter of months, not years.
Remember the principle: as long as the line lives, the number is yours. The day it dies, the number ceases to exist for you — and no customer service team will be able to "get it back".
The three ways to keep a number for next to nothing
Option 1: the prepaid SIM card
In theory it's the cheapest option, and in practice the most treacherous.
How it works: you buy credit (€5, €10, €20), you use it as you go, and each top-up opens a validity period. As long as you're within that period, the line is active and receives calls and SMS.
What almost nobody reads in the terms and conditions:
| Item | What to check |
|---|---|
| Top-up validity | Often 1 to 6 months depending on the amount loaded. Small top-ups come with the shortest validity. |
| End of validity | Remaining credit becomes unusable, and the line switches to "incoming only" before being suspended. |
| Automatic termination | After a period of complete inactivity (frequently in the region of 6 to 12 months depending on the operator), the line is terminated and the number lost. |
| Credit carry-over | With some operators, a new top-up reactivates unused credit; with others, it's lost for good. |
The only reliable method: write the validity expiry date in your calendar with a reminder a week before, and top up the minimum at each deadline. An annual top-up of €10 to €25 is often enough to keep a prepaid line alive — less than €2 a month.
Watch out for the hardware side: a prepaid SIM left in a phone that's never used is a phone that ends up flat, and therefore silent. If that line is meant to receive bank codes, it's better to keep it in a device that's genuinely switched on, or to have a backup power bank on hand for the stretches when the device is asleep in a drawer.
Option 2: the minimal €2 plan (or equivalent)
This is the option I recommend nine times out of ten, and in real terms it's often cheaper than prepaid.
Entry-level offers from French operators hover around €2 a month for a few hours of calls, a limited or unlimited SMS allowance, and a token data bundle (50 MB to a few hundred MB). Some operators even offer a €0 plan reserved for their fibre subscribers.
Its advantages over prepaid:
- No expiry date to keep track of. The direct debit maintains the line all by itself.
- No risk of termination for inactivity. You're paying, so the contract lives.
- No commitment, in virtually all cases: cancellable at any time with a short notice period.
- The number remains portable at any moment, since the line is fully active.
Annual cost: €24. That's the price of a French number reachable 365 days a year, with a genuine contract, an invoice and customer support.
The only real drawback: out-of-bundle charges. With a 50 MB allowance, an app update triggered by mistake can rack up several euros in overage. Hence the golden rule in the next section.
Option 3: a secondary line on an existing plan
If someone in the household is already a customer with an operator, there's often a "multi-line" or "additional SIM" offer at a reduced rate. The secondary number then lives on the main account, with a single bill.
This formula makes sense for a teenager's line, an elderly parent's, or a lightly used work number. It has one downside: the contract holder is the owner of the main account, which complicates any later separation (you'll need to port the number out to detach the line).
The five settings to configure on a dormant line
A rarely used line is a poorly monitored line. That's exactly where nasty surprises crop up: €40 of out-of-bundle charges on a €2 line, or worse, a hijacked line that nobody notices.
1. Turn off mobile data at device level. Not just the quick on/off toggle: in the settings, disable background data for every app, and if the device allows it, set a data cap with automatic cut-off.
2. Enable premium-rate service blocking. All French operators offer free blocking of premium-rate numbers and SMS+ services (purchases by text message). On a dormant line, this is essential: a premium-rate SMS subscription signed up to by accident can run for months without anyone reading the bill.
3. Set a non-trivial PIN on the SIM. If the line receives banking authentication codes, the SIM is a security key. A PIN of 0000 or 1234 makes no sense here.
4. Check the bill at least twice a year. A €2 line paid by direct debit is a line nobody ever looks at. Set a six-monthly reminder: log in to your account, read the itemised details, confirm no option has been added.
5. Record the number, the RIO and the operator somewhere other than the phone. If the device is lost, the RIO becomes hard to obtain. A paper password notebook filed with your admin paperwork does the job nicely, and avoids keeping all the critical information on the one device most likely to go missing.
The special case of bank codes and strong authentication
This has become the number one reason for holding on to an old number.
Since the implementation of the European payment services directive (PSD2), online payments require strong authentication. Many French banks still rely, for all or part of their customers, on sending a code by SMS — or on a mobile app whose initial activation goes through an SMS.
Two concrete consequences:
- A dormant line used for banking authentication isn't incidental: it's critical. If it goes down (expired credit, flat phone, terminated SIM), you lose access to your online payments at the worst possible moment.
- It should be protected like a payment method. Number hijacking — having your line ported to another operator without your knowledge — is a real thing, and Arcep has in fact launched work on telephone identity fraud. Ask your operator, where it's offered, for porting lock or an alert whenever a RIO is requested.
Ideally, you'd gradually move away from SMS as a second factor. Authenticator apps, or even a physical FIDO2-compatible security key where the service supports it, are more robust than a code received by text. But as long as the bank doesn't offer the alternative, the line has to stay alive.
Do you really need a phone switched on at all times?
Not necessarily — and this is where you can save twice over.
Three possible setups:
The SIM in your main phone, as a dual SIM. This is the simplest solution if the device handles two lines — physical + eSIM, or two physical SIMs. The secondary number stays reachable without any extra hardware. One caveat, though: some devices don't keep both lines on 4G/5G simultaneously, which can degrade reception on one of them.
The SIM in a very basic second device. A simple button phone lasts one to two weeks on a single charge, which makes it an excellent home for a dormant line. Plug it in once every ten days and it stays reachable. It's also the most straightforward option for an elderly person.
The SIM in an old smartphone in a drawer. It works, but only if someone remembers to charge it. An ageing smartphone with a tired battery will drain in two days just sitting on standby. If that's your setup, a multi-port charger by the front door solves the problem far better than good intentions.
One technical point to plan for: if the dormant line relies on an older device, check that it properly supports VoLTE (voice over 4G). With the gradual shutdown of 2G and 3G in France, a device that can only make calls over 2G/3G will go silent for voice, even with a perfectly active line. It's the kind of failure you only discover the moment you need the line.
And if the number is already lost?
Let's be honest: in the vast majority of cases, there's nothing to be done.
A few avenues nonetheless, in order of effectiveness:
- Act within days. If the termination is very recent, a call to customer service can sometimes result in reactivation. It isn't a right, it's a commercial favour. Press your case (banking use, work number).
- Check whether it's a suspension rather than a termination. On prepaid, a line that has reached the end of its validity often goes through a suspension phase that a simple top-up can reverse. Read the exact wording of the SMS or email you received.
- Organise the transition if it's final. List the services tied to the lost number — bank, tax authorities, Ameli, government services, delivery platforms, accounts with two-factor authentication — and update them with the new number before circulating it. Order matters: start with the bank and any SMS-authenticated accounts, which are the hardest to unlock later.
And if you simply need to tell a lot of people about a change of number, sending SMS online through a free service saves you doing it one contact at a time from a handset — that's precisely what those tools exist for.
And finally, the maths
Let's put the figures side by side for a number used to receive SMS and make three calls a year:
| Option | Indicative annual cost | Risk of losing the number |
|---|---|---|
| Conventional plan kept "just in case" | €120 to €240 | None |
| Minimal no-commitment plan | ~€24 | None as long as the direct debit goes through |
| Properly maintained prepaid SIM | €10 to €25 | Real, if you miss a deadline |
| Forgotten prepaid SIM | €0 | Near certain |
The conclusion is simple: the €2 plan is almost always the right trade-off. It costs the same as a well-managed prepaid SIM, without the mental load of an expiry date, and it keeps your right of use over the number intact.
And if that dormant line has been dormant for three years without you knowing why you're keeping it, the useful exercise isn't optimising its price: it's checking which services are still attached to it. Half the time, the answer justifies the €24 a year. The other half, it justifies cancelling.
Sources and useful references
- Arcep — numbering plan, allocation of 06/07 blocks, porting rules and number quarantine periods.
- French Postal and Electronic Communications Code — status of numbers as a public resource, right of use.
- Arcep market observatory — data on the decline of the prepaid base in France and the average bill per SIM card.
- Your operator's general terms and conditions of sale — the only enforceable document for top-up validity periods and termination deadlines for inactivity. They differ from one operator to another: read yours.
