In 2026, the variable contract remains the cheapest formula for the vast majority of Belgian households — but it is also the one that exposes you most. A fixed contract buys peace of mind, and that peace of mind has a price: in April 2026 the CREG measured the energy-component gap between fixed and variable contracts at up to 29% for gas and up to 50% for electricity. As for the dynamic tariff, it rewards only one very specific kind of household. Here is how to decide without kidding yourself.
Fixed, variable, dynamic: what is the actual difference?
The three formulas differ on a single point — how often the price per kWh is recalculated — but that point changes everything.
The fixed-price contract locks the energy price for the entire term, generally twelve months. What you sign is what you pay, even if the markets collapse or soar the next day.
The variable-price contract applies an indexation formula: the price is recalculated at regular intervals — monthly or quarterly depending on the supplier — based on a wholesale market index. Your bill follows the market, in both directions.
The dynamic-price contract takes the logic to its extreme: the price changes every hour, tracking the Belgian electricity exchange (EPEX SPOT Belgium). It requires a digital meter. Available in Flanders and Brussels, it has also been available in Wallonia since 1 January 2026.
What does the security of a fixed contract really cost?
Far more than most people think, and the gap widened in 2026.
In its April 2026 findings, the CREG noted that the energy-component price gap between fixed and variable contracts had widened again: up to 29% for natural gas, and up to 50% for electricity. The regulator uses a phrase that sums up the situation well: this difference is a "risk premium", the price of a certain peace of mind for the consumer.
In practice, this means the household signing a fixed contract today accepts paying noticeably more than its neighbour on a variable one, from month one — betting that markets will rise enough to make up that gap over twelve months. That is a bet, not a precaution.
Is the variable contract the default best choice in 2026?
For most households, yes — provided you accept a bill that moves.
With a gap of this magnitude in favour of variable, the maths clearly leans one way. Instalments track the market, which means a fall in wholesale prices reaches your bill within a few weeks, with no action on your part. Conversely, a sharp rebound in prices also lands in your letterbox.
The real risk of a variable contract is therefore not strictly financial, it is psychological and budgetary: a hefty year-end settlement invoice, on an already tight budget, does real damage. If one month at +€80 puts you in difficulty, statistical logic will not console you.
What you gain: the lowest price on the market in 2026, immediate benefit from any fall in prices, and nothing to do to enjoy it. What you accept: an unpredictable bill from month to month, a potentially heavy annual settlement, and an indexation formula that can be hard to decode depending on the supplier.
Who is the dynamic contract really for?
A minority of households — and the figures confirm it.
According to the CREG, dynamic tariffs accounted for only 0.40% of the Belgian residential market at the end of 2025, versus around 25% for fixed tariffs. That is no accident: dynamic pricing rewards one thing only, the genuine flexibility of your consumption.
The profile that wins is the one able to shift significant kWh to off-peak hours: an electric car charged overnight, a controllable heat pump, a home battery, a solar installation whose injection is valued at market price. For that household, the savings add up.
The profile that loses is the one that signs out of curiosity and keeps consuming as before. Without strictly adapting habits, the bill can rise by around 15%. On top of that comes a standing charge that is far from trivial: in May 2026, it averaged around €70 per year on dynamic offers, with peaks up to €130 (Test-Achats, May 2026).
The dynamic tariff does not reward those who consume less, but those who consume at a different time of day.
How do you read the indexation clause of a variable contract?
By looking for three things, in the specific terms and conditions — never in the advertising.
The reference index. Which wholesale market is the price pegged to? Not all indices move at the same pace or with the same amplitude.
The revision frequency. Monthly or quarterly? A quarterly revision smooths out the jolts, but also delays the benefit of any price fall.
The coefficient and the fixed term. This is the supplier's margin, added on top of the index. Two contracts pegged to the same index can carry very different margins — and that, more often than not, is where the gap between two apparently identical "variable" offers is decided.
Add to that the annual standing charge, independent of your consumption. Comparing prices per kWh without it makes no sense: for a small consumer, it can completely overturn the ranking.
Which contract should you choose for your profile?
Four situations cover most cases.
You have a tight budget and dread the unexpected. Fixed still makes sense, despite the extra cost — you are not buying a good price, you are buying certainty. Own that trade-off.
You have a financial cushion and a one-year horizon. Variable is mathematically the better choice in 2026. Mentally provision for a few expensive months and let it run.
You have an electric car, a heat pump or a home battery, and a digital meter. Dynamic deserves a serious calculation, based on your actual load curves.
You have not changed contract in over three years. Your problem is not the contract type: it is the supplier. Look first at the energy supplier ranking, then pick the formula. The order matters.
Key takeaways
Variable and dynamic prices move every month — sometimes every hour: every figure quoted here is dated (CREG, April 2026; Test-Achats, May 2026) and should be re-checked at the moment you sign. Before choosing your formula, start by checking which energy supplier is best placed for your profile — and if you are still unsure how to proceed, our guide on how to switch energy supplier in Belgium sets out the full procedure.
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Camille suit le marché belge de l'énergie depuis une dizaine d'années. Elle a d'abord travaillé côté gestion de contrats B2B, puis est passée à l'analyse indépendante : elle éplucha les grilles tarifaires de Mega, Bolt, Engie, Luminus, TotalEnergies, Eneco ou Ecopower, recoupe chaque prix avec le CREG Scan, la CWaPE, le VREG et Brugel, et refait les calculs de facture à la main quand un fournisseur communique un chiffre trop rond. Sa conviction : la plupart des ménages belges ne changent jamais de fournisseur et paient chaque année quelques centaines d'euros de trop — pas par paresse, mais parce que les offres sont volontairement illisibles. Ici, elle traduit les conditions tarifaires en euros par an, et dit clairement quand une « promo » n'en est pas une.