Family mobile plan: who pays when a line leaves

A family mobile plan is an account in one person's name, who answers for every line, with a per-card discount that depends on how many lines are still active. When a member leaves, the others' discount is recalculated. And the phone they take with them is still the holder's to pay.

One holder, a conditional discount

I saw it dozens of times at the counter in Namur. A parent opens four lines, the children grow up, the eldest gets a job and wants "her" line in her own name. She then finds out that the number she has used for nine years was never hers.

That is the thesis of this article, and I state it up front: the Belgian family plan is not a group tariff. It is an ordinary contract, signed by one person, onto which cards are stacked. The discount is not a price, it is a condition tied to the number of cards. It disappears when the condition falls away.

Orange Belgium writes it in article 5.2 of its mobile general terms (October 2024 version, consulted on 12 October 2026): the customer is "seul responsable", solely responsible, towards the operator for use of the service, "même s'il a inscrit plusieurs Utilisateurs", even when several users are registered. Proximus says the same in article 9.2 of its own terms: the customer answers for use of the card by any person whatsoever. The children, the partner, the grandmother: legally, they are users. The holder is the only customer.

How much does a second line save at Orange, Proximus and Telenet?

Between €1 and €10 per card per month, depending on the operator, the plan and whether there is fixed internet.

Recorded on 12 October 2026 on the three operators' public pages. Amounts are monthly discounts, VAT included. Where the operator does not publish, the cell stays empty.

Commitment periods appear neither on Orange's plans page nor on the Proximus pack page, which presents itself as cancellable at any time: I mark them "not published" rather than guess. Orange Belgium's page on the multi-product advantage and the Proximus packs page are the ones used for the recording.

The right-hand column is the only one that matters for what follows. Orange is the only one of the three to state in black and white what happens when a line leaves: the advantage is "automatiquement annulé", cancelled automatically, if the pack or fixed internet is terminated, if the subscription moves to a non-compatible plan, or "s'il ne reste plus qu'un seul abonnement mobile compatible", once only one compatible mobile subscription remains. Proximus and Telenet do not say so in the pages I read.

The children leaving costs the parent who stays €3 a month

I ran the numbers on a typical household at Orange Belgium, at list prices recorded on 12 October 2026, so after the twelve-month promotions end: a parent on Unlimited at €40, an elder daughter on Medium at €23, a younger son on Small at €15, and an Orange internet pack on the same account.

The first departure costs those who stay nothing: two cards are enough to keep the full discount. The second pushes the parent's line from €30 to €33, which is €36 a year for a line where nothing changed. And moving house is the real surprise: cancelling Orange internet loses €16 a month across the three mobile lines, €192 over a year, without anyone touching a plan.

None of this is hidden. It is written, in the conditional tense of advantage tables, on a page nobody rereads at the moment of leaving.

Who can take the number?

The user can leave with it, but needs the holder to do so.

Porting a Belgian number is started at the new operator. For a postpaid line, Proximus asks in its FAQ for the customer number of the account at the current operator. That number is on the bills, which go to the holder, and in a customer area the user generally cannot access. Without it, the request stalls.

The other route is to move the line into the user's name at the same operator, before leaving or in order to stay. Orange Belgium frames it in article 7.2 of its general terms: the customer may only transfer their rights and obligations with the operator's "autorisation préalable et écrite", its prior written consent, and a transfer form signed by both parties. Article 2.5.7 adds that whoever takes over another person's contract "reste lié", stays bound, by the original contract period. You inherit the calendar along with the number.

Either way, the order does not change: you subscribe at the new operator, and it is the one that closes the old line. A holder who terminates their daughter's card themselves "to keep things simple" makes her lose her number. The full procedure is in the article on switching operator while keeping your number.

The objection: a few euros, and the law lets you leave after six months

This is the serious objection, and part of it holds. The discounts are modest, €3 a month on the parent's line in my example. And Belgian telecoms law lets you terminate a contract with no early termination fee beyond the sixth month of performance, fixed-term contracts included, as the BIPT points out. A line that leaves after two years costs, in fees, nothing at all.

On the service, I have nothing to add.

The objection's weakness lies elsewhere: it reasons line by line, whereas the account is a whole. The six months protect the line that leaves. They say nothing about the discount on the lines that stay, nothing about the internet pack that a share of those discounts depends on, nothing about the plan reserved for the second card, and nothing about the phone financed in the holder's name, which stays due whatever happens. The cost of a departure is not read on the line that goes, it is read on the next bill, by those who stayed. At Orange, article 2.5.6 also ties the duration of an additional card to that of the main card: on this account, the lines do not each live their own life.

Does the leaving line take its phone balance with it?

No. The balance stays with the holder.

A phone taken with a family line is financed on the account, so in the holder's name. When the line leaves, the rest of the amortisation schedule becomes payable, as the BIPT states for every case of termination. On the site's reference handset, €599 of which €598 is financed over 24 months at €24.92, €274.08 remains at month thirteen. The parent gets the bill, not the eldest who has the phone in her pocket. The month-by-month detail is in the article on the 24-month credit behind the €1 phone.

What happens to a Child line left on its own?

Nobody says. Orange Belgium reserves its €5 Child plan "à partir de la 2e carte", from the second card, two at most per account. The page does not say what happens to a Child card left alone after the other lines leave. I mark it "not published". Ask the question in writing before organising the other members' departure.

Points to get in writing before adding a line

The moment to negotiate is when you add, not when you leave. Before signing for an additional card, ask in writing for:

• the exact discount on each card, and the number of cards below which it falls away;
• whether the discount depends on fixed internet on the same account, and what becomes of it if you move;
• the commitment period of the added card, and whether it follows that of the main card;
• whose name the new line's phone is financed in;
• the procedure and cost of a change of holder, for the day the user wants the line in their own name;
• what becomes of a plan reserved for the second card, such as Orange's Child, if it ends up alone.

The answer does not change whether you live in Namur, Brussels or Ghent: electronic communications law is federal.

In a dispute over a withdrawn discount or a line the operator refuses to transfer, write to the operator first. Without a useful answer, the Telecommunications Ombudsman Service handles the case at no cost to you.

Sources

• Orange Belgium, "L'avantage multi-produits expliqué" page and mobile plans page: per-card discount amounts, conditions for cancelling the advantage, Child plan, consulted on 12 October 2026.
• Orange Belgium, general terms for postpaid services, October 2024 version: articles 2.5.5, 2.5.6, 2.5.7, 5.2, 7.2 and 9.2, consulted on 12 October 2026.
• Proximus, Internet, mobile and TV packs page: €5 off for life per additional line, consulted on 12 October 2026; Flex+ FAQ on porting and the customer number, consulted on 12 October 2026; general terms of the mobile communication service, version of 16 August 2021, article 9.2.
• Telenet, ONE products page and terms of the mobile offer running from 5 October to 1 November 2026, consulted on 12 October 2026.
• BIPT, the Belgian telecommunications regulator, termination of a contract and the six-month rule, value still due on a bundled device, consulted on 12 October 2026.
• Telecommunications Ombudsman Service, handling of disputes between consumers and Belgian operators, consulted on 12 October 2026.
• The site's amortisation schedule: €599 reference handset, €1 down payment, linear financing over 24 months, recorded 24 August 2026.