Fixed or variable electricity contract in Belgium

In Belgium, a variable contract costs less over time, because a fixed price includes a risk premium the supplier bills you for. Fixed makes sense when you cannot absorb an increase. But the real gap lies elsewhere, between two fixed contracts.

Fixed or variable: which costs less?

Variable, statistically. CREG, the federal regulator for electricity and gas, is explicit: without active contract management, a household pays less on a variable deal over the long run, because fixed-price products carry a larger risk premium, passed on in the bill.

Fixed therefore buys something other than savings. It buys predictability.

A fixed price locks only 40 % of your bill

This is the misunderstanding that comes up most often in reader questions. Signing a fixed contract does not freeze the amount leaving your account each month.

The energy component accounts for roughly 40 % of a Belgian electricity bill. The rest splits between network costs, around 36 %, and taxes and levies, around 24 %. A fixed price touches only the first column.

The other two move without asking you. Distribution tariffs are set by the regional regulator for a multi-year period, with an adjustment on 1 January. CWaPE, the Walloon energy regulator, approved the 2026 to 2029 Walloon tariffs in June 2025: they bring the average household distribution cost to about 327 € excluding VAT, nearly 8 % more than the previous year, and up to 15 % for some single-rate profiles. On the same date, VREG, the Flemish regulator, recorded a 4 % decrease.

Two households on the same fixed contract therefore saw their bills move in opposite directions, depending on their region.

Should you switch to a fixed contract when prices are rising?

That is exactly the moment to look twice. A fixed price is signed at the price of the day, and the price of the day is sometimes the worst of the year.

The monthly readings published by Test-Achats, the Belgian consumer association, show it without ambiguity. In Wallonia, the average price of a fixed electricity contract went from 14.18 c€/kWh in March 2026 to 19.76 c€/kWh in September 2026, energy plus 6 % VAT. In Flanders, the same average climbed from 13.97 to 19.51 c€/kWh. For a household on 3,500 kWh, that is about 195 € more over a full year, purely because the signature came six months later.

The safety reflex arrives after the rise, never before. Signing in September 2026 meant locking in a rate nearly 40 % above the spring level for twelve months.

That does not make fixed absurd. A fixed contract protects you from the future, not from the past.

Brussels: only two suppliers offer a fixed price

The fixed-or-variable debate assumes both options exist. That is not true everywhere.

The count comes from our reading of the September 2026 Test-Achats monthly survey. In Wallonia and Flanders, seven suppliers feed the fixed-price market, from Engie to Mega via Luminus, Eneco, OCTA+, TotalEnergies and EnergyVision. In Brussels, the list narrows to TotalEnergies and Engie, for five contracts in total. A Brussels resident who wants a fixed price is not really choosing a supplier: they are choosing between two houses. The gap between cheapest and dearest there reaches about 124 € a year for 3,500 kWh, against 379 € in Wallonia. Narrower market, poorer trade-off.

Flanders adds a layer that neither fixed nor variable covers: the capacity tariff, billed at 52 to 60 € per kW of peak depending on the distribution network operator, known locally as a GRD or netbeheerder. At the average Flemish monthly peak of 4.24 kW recorded by Fluvius, that line weighs 220 to 254 € a year, whatever your contract type.

Which contract for which profile?

The right trade-off depends less on your consumption profile than on your ability to absorb a bad surprise. A heavy user with cash in hand can perfectly well stay on variable. A small user on a tight budget can legitimately pay to sleep soundly.

How much does the wrong fixed contract cost?

More than the debate itself. In September 2026, the cheapest Walloon fixed contract sat around 13.57 c€/kWh, while the market average stood at 19.76 c€/kWh. The 6.19 c€ gap represents about 217 € a year on 3,500 kWh, and the full spread between the cheapest and the most expensive contract reaches nearly 379 € according to our calculation on the same survey.

In other words, choosing badly inside the fixed family costs twice as much as choosing the wrong family. The question "fixed or variable" takes all the attention while the question "which one" carries more weight.

Five things to check on the tariff sheet before signing, whatever the contract type:

• The annual standing charge, which sits on top of the price per kWh and is sometimes owed in full even if you leave before expiry.
• The real duration, one year in most cases, three years for some Flemish fixed offers.
• The indexation formula on a variable contract, with its recalculation frequency, monthly or quarterly.
• The welcome discount, often limited to the first year and absent from the headline price in the second.
• The date the quoted price was recorded, because a September rate has nothing to do with the same rate in spring.

What happens when your contract expires?

Two very different mechanisms, and CREG takes care to separate them. Tacit rollover extends your contract on the same terms, with no action from you. Renewal replaces your contract with a new offer that the supplier usually sends two months before expiry. If you do not reply, the general terms treat that proposal as accepted.

That is where hundreds of euros vanish every year, in a letter read diagonally.

Nothing forces you into it, though. Whatever the duration of your contract, Belgian law lets you leave with one month of notice and bans any early termination fee. Our guide on cancelling an electricity contract sets out the procedure and the channel for each supplier.

The right habit fits in one line: compare at every expiry, never just once. Our ranking of the best electricity suppliers and the bill simulator give the real annual cost for your consumption. If you lean towards safety, our selection of the best fixed-rate offers goes into detail, and the article on the dynamic tariff covers the third family. On the official side, the federal regulator's CREG Scan and the tariff pages of Brugel, the Brussels regulator, complete the check.