Landline number portability: keeping your number in Belgium
Keeping your landline number when you switch provider or move house: the porting delay, the telephone zone rule and the compensation if the old provider stalls.
Yes, in most cases, with one condition nobody mentions when you sign: the number has to stay in its telephone zone. Switching provider at the same address keeps your 02, your 04 or your 071. Moving to another zone does not. And the only move that really loses a number is cancelling the old line before the new one has taken it over.
Can I keep my landline number when I switch provider?
Yes. Test-Achats (the Belgian consumer organisation) sums it up: you just fill in a number transfer form with your new provider, who does the rest. In a bundle switch, the request travels with the Easy Switch file, which is free; our article on downtime when switching provider details the steps.
The wording varies with the network carrying your line: copper or fibre at Proximus (and at Scarlet, which sits on the Proximus network), cable at Telenet in Flanders and Brussels, Walloon cable at Orange since it took over VOO. The rule does not vary.
How long does porting a landline number take?
One working day at most. It is the only really binding delay in a provider switch, set by the royal decree of 2 July 2013 and recalled by the BIPT. Everything else depends on the connection appointment: Test-Achats gives from 3 days to 6 weeks to install the new line.
Lateness costs money. A late port is worth 3 euros a day per number, or 5 euros a day from two numbers, to be claimed within six months. Thirty days of delay on a single number therefore make 90 euros, calculated on 29 September 2026 from the BIPT scale.
Why the telephone zone decides everything
Because a geographic landline number is not a personal possession: it is a piece of territory. In its consultation of 28 January 2009 on the future of geographic numbers, the regulator recalled that these numbers can only be assigned to users whose connection is physically inside the zone. Porting between operators within the zone: allowed without restriction. Porting outside the zone: forbidden.
Three scenarios were on the table, from removing the geographic link to keeping it strictly. I found no more recent text that lifts the rule, and Proximus still applies it in 2026; treat it as in force, and check with your provider before counting on anything.
What happens to my number if I move house?
It all depends on the destination zone. On its help page, checked on 29 September 2026, Proximus writes that moving within the same telephone zone (the 02 area, for example) lets you keep your number free of charge, "even if you are a new customer", and promises contact within 24 hours. If the zone changes, a new number is assigned automatically.
Zones do not follow provinces. Enghien, in Hainaut, is in the 02 zone like Brussels; Mouscron, also in Hainaut, is in 056 with Kortrijk. Our table of the 40 zones lets you check the destination address, and our guide to moving with the same provider or elsewhere settles the rest of the contract.
Which case, which answer?
| Your situation | Does the landline number follow? | Delay or cost to know | The useful move |
|---|---|---|---|
| Switching provider, same address | Yes | Porting: one working day at most | Give the Easy Switch identifier or sign the transfer form |
| Moving within the same zone | Yes | Free at Proximus, contact within 24 h | Announce the move and explicitly ask to keep the number |
| Moving to another zone | No | New number assigned automatically at Proximus | Warn family and update bank, health fund, doctor |
| Landline alone, no internet or TV | In principle yes | Easy Switch assumes internet or TV: port by form | Get the new provider's written agreement before cancelling |
| Old contract cancelled before the port | Risk of loss or blocking | Public case: 70 euros monthly charges according to the complainant | Cancel nothing yourself |
| Call forwarding to a mobile | No, it is not porting | The number stays on the old line | Use it only as a stopgap |
Table built on 29 September 2026 from the Proximus help page, the BIPT's 2009 consultation, the BIPT scale for late porting and a public Test-Achats complaint. Telenet, Orange and Scarlet rules for a move are to be checked with them.
What if the old provider keeps my number?
On 24 November 2023, a subscriber filed a public complaint with Test-Achats. He had moved from Telenet to Proximus on the promise of a better all-inclusive landline rate. His old 02 number was not taken over, it stayed at Telenet and cost him 70 euros more a month, he says, while the new Proximus number sat unused. Proximus replied on 13 December; the case is marked resolved.
The story does not say what jammed. It does show what a forgotten number costs: over six months, 70 euros a month makes 420 euros, nearly five times the 90-euro porting delay seen above. The way forward takes three steps:
- Write to the provider you left, with the date of the porting request and proof it was filed.
- Claim the delay compensation from the new provider, within six months.
- Take the case to the Telecommunications Ombudsman Service, free for consumers, if nobody moves.
Five mistakes that lose a landline number
- Cancelling the old contract by letter before the new provider has taken the number over.
- Moving to another zone thinking the new contract "keeps everything".
- Forgetting to say, on the moving call, that you want to keep your number.
- Mixing up call forwarding and portability.
- Assuming the mobile in a bundle follows a mobile subscription signed separately.
The trap to avoid is the first: it looks responsible and it costs the most.
Does call forwarding replace portability?
No. Forwarding makes your mobile ring when someone calls the old line, but the number stays attached to the old contract, hence to its bill. Useful for three days so you do not miss the notary, useless for leaving.
Sources: IBPT/BIPT (consultation of 28 January 2009 on the future of geographic numbers; page on late porting; 2008 decision on portability costs), Test-Achats (Easy Switch, 9 November 2023; public complaint of 24 November 2023), Proximus, help page on your phone number when you move (checked on 29 September 2026).
Frequently asked questions
Maxime suit le marché télécom belge depuis dix ans. Il épluche les grilles tarifaires de Proximus, Orange, Telenet, VOO, BASE et des MVNO pour traduire le jargon (VDSL, câble, Easy Switch, 4play) en conseils utilisables.