Energy supplier: the lever you can pull in a month

Insulating a roof takes months and costs thousands of euros. Switching supplier takes one month's notice and costs nothing — no exit fee, even on a fixed-price contract with a set term. The federal regulator says so in black and white. What is left is understanding what you actually pay: on an electricity bill, energy is only 38%.

This site has sixteen pages on energy. They all explain how to use less: insulate, replace a boiler, fit panels. None of them explained how to pay less right now, with no building work. That is what this one is for.

One month's notice, no exit fee

1 month
notice, at any time
€0
exit fee
All
contracts, fixed and variable alike

CREG's wording leaves no room for interpretation: “Whether the contract is fixed-term or open-ended, a consumer may cancel their energy supply contract at any time subject to one month's notice. The supplier may not charge them any exit fee.

That also applies to a fixed-price contract. CREG repeats it about those contracts: if prices fall, you do not benefit, “unless you switch contract in the meantime, which you can always do, free of charge, subject to one month's notice”.

⚠️ One thing only to check: the standing charge. CREG warns against fixed-price contracts that come with a high fixed standing charge, especially when it is billed in full even if you switch before the end of the term. It is not an exit fee — it is legal — but the economic effect comes close. That is the line to read before you sign.

What you really pay

Before switching supplier, you need to know what the switch actually acts on. The answer: on part only of the bill.

Component Electricity Natural gas
Energy — the only part the supplier sets38.19%59.86%
Network costs — distribution and transmission29.86%20.43%
Levies and surcharges26.30%14.04%
VAT6%, i.e. the remaining 5.7% or so
💡 What that means in practice

On a gas bill, the share you can put out to competition is more than half the amount: switching supplier has a direct and sizeable effect.

On an electricity bill, it is only a little over a third. An offer 10% cheaper on energy therefore cuts the total bill by only about 4%.

Network costs do not depend on the supplier but on the distribution system operator for your municipality: they are the same whatever the offer. Levies cover the energy contribution, excise duties, the Walloon connection charge, the Flemish energy fund contribution, the Brussels public service obligations surcharge, and the costs linked to green electricity and cogeneration.

Fixed or variable: what you are really buying

Fixed price
You are buying predictability
The price per kWh stays the same for the whole term of the contract
On a fixed-term contract, the supplier cannot change it before the end date
If prices fall, you do not benefit — but you can leave with 1 month's notice
Variable price
You are following the wholesale market
The price follows an indexation formula, usually monthly or quarterly
The formula is public and tied to quotations on the energy exchanges
On an open-ended contract, the supplier can change it subject to notice

One thing to watch on fixed-term contracts: suppliers generally set a two-month notice period before the end date in which to offer a renewal, and their terms and conditions treat that offer as accepted if you do not react. That is how you end up rolled over onto an offer that is no longer competitive.

The indexes, in plain terms

An indexation parameter is, in CREG's words, “a variable element of the price formula used to determine the variable energy price”, with a clear link to quotations published by the energy exchanges. The names are opaque but the logic is simple.

Index Energy What it measures
Endex101ElectricityAverage closing quotations of Belgian futures for the month before the month of supply
Endex103ElectricitySame, but for the month before the quarter of supply
Belpex DAMElectricityAverage monthly price on the Belgian day-ahead market
TTF101GasAverage of ICE Dutch TTF futures for the month before the month of supply
TTF103GasSame, for the month before the quarter
ZTP101GasEEX Gas ZTP futures, monthly basis
✅ The rule to remember

101 = monthly indexation. 103 = quarterly indexation. A 101 index reacts faster, up and down alike. A 103 index smooths more. That is all you need to compare two variable offers.

The social tariff: identical at every supplier

This is the most misunderstood point: the social tariff is the same at every supplier. Being entitled to it makes comparing pointless — and switching supplier of no use.

Social tariff, Q3 2026 Total, incl. 6% VAT
Electricity, single rate24.927 c€/kWh
Electricity, dual rate day26.797 c€/kWh
Electricity, dual rate night23.328 c€/kWh
Natural gas and heat5.458 c€/kWh

The amount is set by CREG, but eligibility is handled by FPS Economy. It is recalculated every three months, starting from the cheapest commercial tariff on the market, with caps on increases: 10% against the previous quarter for electricity, 15% for gas.

It has been automatic since 1 July 2009 for people on CPAS, FPS Social Security and Federal Pensions Service benefits, and it is extended automatically the following year if the entitlement still stands. The automation can fail where there is an inconsistency with the National Register — which is why it is worth checking for yourself through the FPS Economy online service.

⚠️ One category is not automatic. Social housing tenants whose heating depends on a collective installation have to apply for it. That is the category that most often misses out on the entitlement.

The official comparison tools, and what they do

1
CREG Scan — to see where you standThe federal regulator's tool compares your existing contract, however old, with what the market offers today. Six questions, updated monthly. It does not let you switch supplier: it is a diagnosis, not a subscription.
2
Your Region's tool — to switchCompaCWaPE in Wallonia, the VREG V-test in Flanders, BRUSIM from BRUGEL in Brussels. These are the ones that list every offer and let you switch.
3
Compare on the right consumptionThe regulators compare using standard consumption profiles: 3,500 kWh of electricity a year for an average single-rate household, 17,000 kWh of gas.

⚠️ The 23,260 kWh figure is out of date. That was CREG's old reference profile for gas. After a survey of network operators, suppliers and consumers in the three Regions, CREG brought it down to 17,000 kWh from 1 April 2022. It is still circulating all over the web: a comparison based on it overstates the bill by more than a third.

A useful benchmark on the Flemish side: consumption actually measured in 2024 was 2,662 kWh of electricity taken from the grid — a figure pulled down by households with panels — and 11,281 kWh of gas, across all households.

The digital meter, unevenly rolled out

🦁 Flanders
80%
At 1 December 2025, that is 2.95 million electricity meters, and 89% among owners of panels. The last 20% started in early 2026, with the roll-out due to finish mid-2029.
🌻 Wallonia
Systematic
since 2023
Systematic installation since 1 January 2023 for new builds, meters due for replacement and customers in payment default. Target 100% by the end of 2029. Replacement is free.
🏛️ Brussels
161,055
meters
At the end of 2025, of which only 3% in data communication mode. No systematic campaign: replacement follows trigger events.
💡 A right of refusal, but a partial one

In Wallonia, since 1 January 2024, you can only refuse the communicating function of the meter — not the meter itself. That refusal has to be notified within 15 days of installation.

The digital meter is what gives access to dynamic contracts, indexed by the hour. In Brussels the first dynamic offers appeared in March 2025; at the end of 2025, five offers were on the table from three suppliers, but barely more than 1% of households in communication mode had signed up.

If you move house

The energy transfer document is how meter readings are passed on when you move in or move out. You fill it in in two copies signed by both parties, each keeping one. It has legal force and serves as evidence in any dispute over the readings. It has to state the transfer date, the address, the meter numbers and the readings. The official forms are published by CWaPE and by BRUGEL.

Key takeaway: the bill composition percentages are those of CREG's half-yearly analysis for H1 2026, for a standard household; your own split depends on your consumption and your distribution system operator. Social tariffs are recalculated every quarter. Use your regulator's comparison tool rather than a fixed figure.