Variable energy contract: how it works
By Laurens Arends · updated 05-10-2026
How a variable energy contract works
With a variable energy contract, the supplier can raise or lower the supply rates for electricity and gas in the interim. Your contract must state when, why and how that may happen. According to ACM ConsuWijzer many suppliers change their rates at fixed moments, for example every quarter or around 1 January and 1 July. The exact moments of change are stated in your contract conditions.
The supplier must announce a rate change at least one month in advance. The message must make clear which rates are changing and from which date. The feed-in fee for solar panels can also change with a variable contract, provided that this possibility is stated in the conditions and you are informed at least one month in advance. The rates of a variable model contract may change a maximum of four times a year. The ACM warns that such a model contract is usually not the supplier's cheapest offer.
Not the whole energy bill is variable. The government sets the energy tax. The ACM sets the rates of the grid operators every year, after which your supplier collects these system management charges via the energy bill. These amounts can also change with a fixed energy contract. The word ‘variable’ therefore refers to the supply prices and other contract rates of your supplier.
Most variable contracts have no fixed end date. You pay no cancellation fee and can switch with the notice period from your conditions. According to ACM ConsuWijzer, that period is a maximum of one month. Some suppliers now apply a shorter period.
Dynamic, fixed or variable energy contract?
Fixed energy contract
With a fixed contract, the agreed supply rates stay the same during the term. Taxes and system management charges can change, however. A fixed contract gives the most price certainty and often includes a welcome discount for new customers. If you cancel a fixed contract before the end date, the supplier can charge a cancellation fee based on its financial loss. So first look at how to choose an energy contract that suits your plans.
Variable energy contract
A variable contract gives you the freedom to leave without a cancellation fee, but no certainty about future rates. Moreover, a price fall on the wholesale market is not passed on automatically or immediately, unlike with a dynamic energy contract. Suppliers buy energy in advance and change variable rates at the moments set out in their conditions.
Dynamic energy contract
With a dynamic energy contract the supply rate moves directly with the wholesale market. The electricity price can change per hour or quarter of an hour and the gas price per day. You need a smart meter for this. This contract has no cancellation fee either, but the price risks are felt more directly than with a variable energy contract. By shifting your usage to cheap hours you can lower costs, but a lower annual bill is not guaranteed.
Pros and cons of a variable contract
The main advantage is that you are not tied down for one or more years. Without a cancellation fee, you can switching and for an ordinary variable contract you do not need a smart meter. That is handy if you are moving soon or do not want to make a fixed choice for now.
Compared with a fixed contract, a variable energy contract can also become cheaper when market prices fall and the supplier passes that fall on. Swedish research among around 54.000 households found an average advantage of 0,06 Swedish kronor per kWh over fixed contracts in the period studied. However, this only concerned electricity and variable contracts that were adjusted monthly.
The outcome of this research is therefore not directly applicable to Dutch households with electricity and gas. Other independent studies also show the opposite. A 2024 evaluation by Nordic Energy Research even calls variable contracts the least competitive contract type in most of the countries studied. So it is not clear whether a variable contract is really a cheap choice in the Netherlands as well.
With a variable energy contract you do not know which supply rates will apply after the next moment of change. A supplier can build a margin into a variable rate for purchasing, volume and price risks. At the same time, you do not benefit from falling market prices as quickly as with a dynamic contract.
In our market comparison of August 2026, variable contracts at several large suppliers were more expensive than their fixed alternatives. That was not the case at every supplier. So always look at the total annual amount instead of just the contract type. Welcome discounts, fixed supply charges and feed-in charges can completely change the outcome.
Current deals for variable energy
| Supplier | Contract | Per month | Per year | |
|---|---|---|---|---|
 VattenfallLowest | Variable | € 233 | € 2.796 | View › |
 DELTA Energie | Variable | € 235 | € 2.820 | View › |
 Greenchoice | Variable | € 235 | € 2.820 | View › |
 Innova Energie | Variable | € 242 | € 2.904 | View › |
 ENGIE | Variable | € 245 | € 2.940 | View › |
The overview shows the current variable deals for your usage. The calculation includes the supply rates, fixed costs, feed-in charges, feed-in fee and any cash discount. Above all, compare the net annual price. The monthly amount is only an advance payment and a current low price can change during the contract. Do you also want to include other contract types? Then look at all deals with the same usage data.
Common mistakes with a variable energy contract
A common mistake is thinking that a variable contract automatically becomes cheaper as soon as the wholesale price falls. The supplier determines the moments of change according to the conditions. A dynamic contract follows the market much more directly.
The instalment amount also causes confusion. An unchanged advance payment does not mean that your rates have stayed the same. According to ACM ConsuWijzer, the instalment amount is only an advance payment towards the annual bill. So check the kWh and m³ price in the change notification and not just the amount that is debited monthly.
Finally, many people unknowingly stay on a variable energy contract after their fixed contract has ended. The supplier must announce the new variable rates at least one month in advance. If you do not want to pay those rates, you can take out a different contract before the effective date. If you remain a customer, the announced rates will apply. Compare again before the end date and plan the switch if another contract is cheaper.
Frequently asked questions about variable energy contracts
A variable energy contract seems simple, but the moments of change and cancellation rules regularly lead to questions. Below you can read the most important differences and when this contract type does or does not make sense.
What is the difference with the other contract types?
With a fixed contract, the supply rates stay the same during the agreed term. With a variable contract, the supplier determines at which contractually agreed moments the rate changes. A dynamic contract follows the market much more directly and requires a smart meter.
Can I cancel a variable energy contract before it ends?
Yes. According to ACM ConsuWijzer, you pay no cancellation fee for a variable energy contract. Bear in mind the notice period in your conditions, which may be a maximum of one month. With a normal switch, the new supplier arranges the termination.
When is a variable energy contract smart?
A variable energy contract can be smart if you want to stay flexible for a while and do not want direct exposure to hourly or quarter-hourly prices. Think of a planned house move or a short bridging period after your fixed contract has ended. If you want to stay longer, first compare the current fixed, variable and dynamic annual prices.
How do I take out a variable energy contract?
Taking out a new energy contract is very easy. First enter your postcode, house number, annual usage and any feed-in. Then compare deals on the basis of the total annual amount and not just on the basis of the kWh or m³ price. After that, compare the total annual amount and check how often the supplier may adjust the rates. After you sign up, a cooling-off period of fourteen calendar days applies. With a normal switch at the same address, the new supplier arranges the termination of your old contract.