Belgian mobile plan prices: the real 24-month calculation

A plan advertised at €34.99 a month costs €46.24 a month over two years. The promotion runs six months, the contract runs twenty-four, and the gap comes to €270. Here is the calculation in five steps, with the real totals of five Belgian plans recorded on 30 August 2026, host network shown.

Why does the advertised price never survive the first year?

Because it was never built to.

Three mechanisms separate the shop-window rate from the amount actually taken over twenty-four months. The entry promotion, which stops on a date known in advance. The annual indexation, which is added and cannot be refused. The handset financing, when a phone enters the deal. None of the three is hidden: all appear in black and white in the terms and conditions, and none appears in the "price" column of a comparison table sorted by ascending rate, which is enough to make that sorting misleading for anyone signing a two-year contract.

The calculation below needs a calculator and five minutes. It produces a single figure, the levelled monthly cost.

The five steps of the calculation

1. Record the base price, not the entry price. The rate that matters is the one that applies once the discount ends. It is always written down, often in small print, sometimes as "then €X per month".
2. Note the exact length of the promotion. Seven or thirteen: the number of the first full-price month decides everything. A six-month discount on a two-year contract covers only a quarter of the term.
3. Add the one-off fees. Activation, SIM card, delivery. They are free online at several brands and charged in store at others, they appear once, and they land on the first bill.
4. Count one indexation per year started. Over twenty-four months you cross at least one, usually on 1 January. Take the rate your operator announces, or failing that the increase applied last year to the same range.
5. Take the handset out of the plan calculation. A financed phone is credit, not a discount. Count it on its own line and compare its total to the cash price of the same model at a retailer.

The result is then divided by twenty-four. That quotient is the only figure comparable from one offer to the next.

What do five Belgian plans really cost over two years?

The table below applies the calculation to five plans on the Belgian market, price lists recorded on 30 August 2026, one-off fees and indexation excluded so the amounts stay verifiable.

Here is the figure of this article. Proximus Mobile Unlimited is advertised at €34.99 and works out at €46.24 a month once levelled over the contract, which is €11.25 more every month and €270 over two years that the entry price does not let you guess. The cause fits in one clause: the discount stops at month six, not month twelve, and eighteen full instalments follow.

A second lesson comes out of the table, less spectacular and more useful. Measured against the two-year total, the promotional discount weighs between 7 and 12 % depending on the offer: €12 saved out of €168 at Mega, €90 out of €1,199.76 at Proximus, €108 out of €960 at Orange. The promotion drives the decision far more than it changes the bill.

Over twenty-four months, the entry discount is less than a tenth of what you will pay. The full price is the other nine.

One correction belongs here, and it reaches beyond this article. yoin does not rent the Orange network but the Proximus one, according to the Selectra operator page consulted on 30 August 2026. The brand-to-network tables circulating on Belgian sites, including some of our own earlier pages, still attach it to Orange. On a market where around fifteen labels share three networks, a takeover or a change of wholesale agreement is enough to make a whole row obsolete without anyone noticing.

Can the annual indexation be refused?

No, not when it is written into the contract, and this is the most misunderstood legal point in the sector.

The BIPT, the Belgian telecoms regulator, draws two situations apart. When your operator changes a condition of the contract, it must warn you at least one month in advance and you may cancel free of charge within the three months that follow the notification. But that right falls away if the increase results solely from the indexation of the consumer price index foreseen in your contract. In other words: the indexation clause, accepted at signature, binds you for the whole term.

The January 2026 increases show the difference. Orange raised its currently marketed mobile plans by €2 to €3 a month, and its legacy plans by €2.60 to €4. The Scarlet Trio pack went from €42 to €45 a month on 1 January, which is €36 more over the year. VOO applied a flat €3 increase to twenty-two packs, six months after a first €2 rise. BASE followed in May 2026.

On a €9 plan, a €2 increase is 22 %. Indexation hurts most in proportion on entry-level plans, never on the premium tiers that get more attention. Read the clause before you sign.

Does the "free" smartphone count in the total?

Always, and on its own line.

A phone "offered" with a plan is a handset financed over twenty-four months, whose instalments are folded into the monthly rate or billed separately. The word "free" describes a payment method, not a gift. Checking it is one subtraction: compare the two-year total of the bundled offer with the two-year total of the same plan without a handset, then add to the latter the cash price of the model at a Belgian retailer. The gap between the two results is the cost of the financing, and it is sometimes negative, which makes the bundle genuinely worthwhile.

This check has a consequence for the commitment period. A plan on its own can be cancelled free of charge after six months in Belgium. A plan attached to a handset usually leaves a balance to settle, and it is that balance, not the telecom contract, that keeps you until the end.

Six mistakes that distort the calculation

Each one has already cost more than it looked like it would.

• Taking the entry price for a monthly price. This is the parent mistake, the one the other five come from.
• Ignoring the real length of the promotion. Six months and twelve months do not produce the same total, at an identical monthly discount.
• Confusing indexation with a tariff increase. The first cannot be refused, the second opens three months to leave free of charge.
• Forgetting the one-off fees. Activation and SIM card weigh nothing over twenty-four months, but they distort the comparison between an online and an in-store subscription.
• Treating the handset as a discount. Credit written into a plan stays credit, and it survives cancellation.
• Comparing two rates without looking at the host network. A cheaper plan on a network with poor reception at your address is not a saving.

When should you leave to avoid the thirteenth month?

At month twelve, or month six when the promotion is short, and Belgian law allows it without argument.

Since July 2022 a telecom contract can be cancelled free of charge after six months, whatever commitment is advertised, keeping your number, with the switch handled by the new operator through Easy Switch. The twenty-four-month horizon therefore serves to calculate a cost, not to hold you. It stays the right unit of comparison, because price lists are built on it.

Put the promotion end date in your calendar on the day you subscribe, not three months after the first full bill. It is the only move on this page that earns money without any expertise at all.

We do not subscribe to these plans and we measure nothing in the field: this page aligns public price lists, operator announcements and the rules published by the regulator, recorded on 30 August 2026. The same calculation, applied to the whole market and sorted on the thirteenth-month price, sits in our 5G plans ranking, host network shown next to every row, and reorders in the comparison table. On large data allowances, we have looked elsewhere at what Belgian unlimited plans are really worth; on coverage, at how to read the regulator's atlas municipality by municipality before looking at any rate.

Sources : BIPT, "Modification by the operator" (one month's notice, cancellation free of charge within three months, exception for contractual indexation) and "Terminating the contract" (free after six months, Easy Switch), consulted on 30 August 2026; Statbel, consumer price index; FPS Economy, consumer protection; Test Achats, files on the 2026 Proximus and Orange tariff increases; L'Avenir, 15 December 2025, on the 2026 increases at Proximus, Orange and VOO; La DH, 21 May 2026, on the BASE tariff increase; Selectra Belgium, "Abonnement GSM le moins cher en Belgique", updated 4 August 2026, and Mega and yoin operator pages consulted on 30 August 2026; Mon-Abonnement-Gsm.be, cheap plans comparison, recorded 20 August 2026; promotion records taken on 29 and 30 August 2026. Official pages of the brands cited: Mega and DIGI. No link on this page is monetised.