Out-of-bundle charges: why your Belgian bill jumped

Out-of-bundle usage is what you consume beyond your plan's allowance, billed separately. In Belgium, the same gigabyte of overage costs €1.80 at one operator and €60.00 at another. But a bill that climbs is not always about going over: four other lines produce exactly the same effect.

What exactly are out-of-bundle charges?

They are the usage that falls outside your included allowance — mobile data, call minutes, texts — and that the operator bills separately, per megabyte or per minute. It shows up on the following month's invoice, under a heading such as "out-of-bundle usage" or "hors bundle".

One clarification that saves a lot of confusion: out-of-bundle charges only exist on a post-paid subscription. With a prepaid SIM, the credit runs out, the service stops, and nobody sends you anything. You lose network access, you do not receive an invoice.

How much does an out-of-bundle gigabyte cost in Belgium?

Between €3.60 and €120. The ratio between the two ends of the Belgian market exceeds thirty, which is probably the least known and most expensive gap in the sector.

Rates checked on 23 August 2026 at Selectra and on 22 July 2026 at Mon-Abonnement-Gsm.be. The two sources disagree on Proximus — €0.12/MB for one, €100/GB for the other. I am not arbitrating: assume the higher figure, it is the one that lands on the invoice.

Two things stand out in that table. First, the operators that charge the most for overage are also the ones that protect you best, with Proximus and hey! cutting you off automatically. The second is more awkward: BASE, edpnet and Scarlet, the cheapest per gigabyte, cap nothing at all by default.

Five hundred forgotten megabytes, sixty euros

One app update launched without Wi-Fi is enough. Here is what that half-gigabyte costs depending on the operator, once the cap is applied.

At Orange and Telenet, count on €50.00. At Mobile Vikings the rate would be identical, but the €10/month cap steps in and you will never pay more than that. Test-Achats, the Belgian consumer organisation, documented the extreme case on 1 July 2026: a €2,000 bill at Proximus after a single night of data consumed outside the allowance.

My bill went up: is it necessarily out-of-bundle usage?

No, and that is the trap. Five different lines produce the same €20 to €40 gap, and only one of them is cured by a blocking option. Before calling customer service, open last month's invoice next to the new one and compare item by item.

The January 2026 increases are worth knowing about, because they never show up in the usage details: Proximus added €2 to €4 a month depending on the plan on 1 January, Orange €2 to €3 a month on standalone internet on 18 January, and Scarlet's Trio bundle went from €42 to €45 a month. No option blocks that. Our method to cut your telecom bill sets out the cancellation window that opens after a notified increase — and the decisive difference between a price rise and plain indexation.

As for those three-digit numbers, they follow their own pricing logic, unrelated to your plan: the full scale is in our article on what a premium-rate number really costs.

Does my operator have to warn me before billing?

Yes, and it is a legal obligation, not a commercial courtesy. Every Belgian operator must send an SMS alert as soon as usage on a post-paid mobile offer crosses a threshold set above the subscription. This is the so-called "bill shock" mechanism, established by the decision of the IBPT — the Belgian telecom regulator, BIPT in Dutch — of 20 November 2012, under article 112 of the Electronic Communications Act.

The default threshold is €50 including VAT above your plan. You are not obliged to live with it: the operator must offer you four levels — plan + €0, + €50, + €75 or + €100. The first one is the only genuinely protective setting, it is free, and almost nobody switches it on. The details are on the IBPT page devoted to the alert mechanism.

What that safeguard does not do, on the other hand, deserves to be spelled out:

• It alerts, it does not block. The text goes out, the usage continues.
• It is set per line, not per contract: on a four-SIM bundle, there are four settings.
• It covers neither premium-rate numbers nor purchases billed by third parties.
• It says nothing about indexation, the end of a promotion or pro-rata charges.
• Outside the European Union, the automatic cut-off applies to data only.
• On some foreign networks, the operator warns by SMS that it cannot guarantee the cap will hold.

How do I block out-of-bundle usage, line by line?

At Proximus, the Full Control option cuts out-of-bundle usage once the allowance is exhausted while letting texts through; it is free and also covers premium-rate numbers, international calls and non-EU roaming. At Orange, National Data Control lets you set a maximum amount from the app. At hey!, the low-cost brand of the same Orange group and therefore on the same network, blocking kicks in automatically at €50.

One reflex matters more than the choice of option: ask for it line by line. On a family bundle, the invoice is single but the settings are not, and it is almost always the teenager's SIM that produces the gap.

And abroad, what is actually covered?

Inside the European Union, nothing to do: your Belgian plan works there on the same terms as at home, and has since 2017, within fair-use limits. Outside the EU, it is another story.

A safeguard does exist. Your operator must suspend mobile internet as soon as your roaming data usage reaches €50 excluding VAT, or €60.50 including VAT, with a mandatory alert at 80 % of the cap. That limit applies inside the Union and outside it. It only covers data. Your calls and your texts keep being billed beyond it, and that is exactly where four-figure holiday bills are made. The IBPT explains how to keep those costs under control, and the FPS Economy, Belgium's federal consumer authority, sets out the general framework of your rights.

Should I pay the overage or change plan?

Look at the frequency, not the amount. A one-off overage gets paid and forgotten. Two months in a row, the question is no longer blocking: it is the allowance.

Moving from a 5 GB plan to a 15 GB one usually costs €3 to €5 more per month, so €36 to €60 over a year. A single gigabyte of overage at Proximus, Orange or Telenet costs roughly the same in one go. The arithmetic does itself, and it almost always leans the same way. This is also the moment to check whether an unlimited-data plan would settle the question for good.

To go further, compare the rates we recorded in our bundle ranking.