If you have a dynamic electricity contract, you have probably heard that prices are "15-minute now". Then you open your supplier's app and see one price per hour, and the two do not obviously fit together.
Both are true. The market changed; what your supplier bills you on is a separate question, and it is written in your contract rather than in the market rules.
Here is the whole thing in plain words.
What changed, and when
Since the delivery day of 1 October 2025, the European day-ahead coupling — the mechanism that matches buyers and sellers across most of the continent and produces the price you hear about — clears in 15-minute periods instead of hourly ones. The decision was confirmed in September 2025 and the switch was reported as implemented on the day itself.
That is the whole of the change at market level: where there used to be 24 prices for tomorrow, there are now 96.
It had been planned for June 2025 and was moved. If you read something in 2024 or early 2025 saying the change was imminent, that is why it did not happen when it said.
Why your supplier may still bill you by the hour
This is the part that confuses people, and it is the useful part.
The market's resolution and your contract's resolution are two different settings. A supplier buying in 15-minute periods can still bill you on the hour's mean — adding up the four periods and charging the average for all of them — and many do, because their billing systems and their customer apps were built when the hour was the only unit there was.
So:
- the price exists in 15-minute periods, published for everyone;
- what you are charged follows your contract, which may use those periods or may use the hour's mean of them.
Neither is a mistake. But if you measure your own consumption, the difference shows up immediately: a kettle that runs during the single expensive 15-minute period of a cheap hour costs you nothing extra on an hourly contract, and costs you the spike on a 15-minute one.
⚠️ This is a thing to read in your own contract, not to guess from the market. If the terms say the price applies per settlement period, you are on 15-minute pricing. If they say hourly, you are not — on a market that is nonetheless 15-minute underneath.
On the hub this is literally a setting: you tell it which of the two your contract uses, and it prices accordingly. Everything else — the sources, the fees, the taxes — stays the same.
Who is entitled to a dynamic contract at all
European law sets a floor here, in the electricity market directive. In short, and without pretending to be legal advice:
- a customer with a smart meter is entitled to a dynamic-price contract;
- larger suppliers must offer one — the directive names a threshold of 200 000 customers, and member states may go further;
- the switch needs your consent, and the supplier must tell you what the contract means, including the risks.
The definition of "dynamic" in the same directive is a contract that reflects the spot market's prices at an interval at least as often as the market settles — a different clock from the day-ahead one this article opened with, and one that was already fifteen minutes before 2025.
Whether an hourly-mean contract meets that definition is a question between a supplier and its regulator. It is not something this article judges, and it is not a reason to go and argue with yours.
⚠️ That article has been amended since it was written, so the version to read is the consolidated text, and the implementation in your country is its own question.
When tomorrow's prices appear
The day-ahead auction closes at noon CET, and results are normally published around 12:45 CET — sometimes later, and occasionally much later when something goes wrong in the coupling. Your supplier's app, and any meter that fetches prices itself, pick them up after that. The hub starts asking for tomorrow in the late morning UTC and keeps asking — every fifteen minutes through the early window, then hourly for as long as the day is still missing — so a publication that slips to the evening is picked up within about an hour of appearing.
Until tomorrow's prices arrive, nothing is left unpriced: periods are covered by today's prices while they last, then by your backup source if you set one, and otherwise by your tariff plan's zone rate. The log says which covered each period, so a strange-looking night can be read back rather than guessed at.
This matters for one practical reason: anything that plans around tomorrow's prices — a cheap-window rule, an automation, you deciding when to run the washing machine — has nothing to plan with until the publication lands. A rule that looks broken in the morning is often just a rule waiting for the afternoon.
What this means if you measure your own consumption
A 15-minute market rewards knowing what happened in each fifteen minutes. That is the only part of this where a meter has anything to add:
- matching the resolution. If your contract prices per period, the energy has to be attributed per period too, or the cost is an approximation of an approximation.
- keeping the price with the energy. A price applied later, from a table, is a reconstruction; a price stored next to the kilowatt-hour it was charged on is a record.
- seeing the hour's inside. On an hourly contract the four periods are one number. On a 15-minute one they are four, and the expensive one is worth finding.
What this article does not tell you
- Whether to switch. A dynamic contract suits some households and not others, the answer depends on when you use energy and how much flexibility you have, and it is not a decision we are in any position to make for you.
- What your country did. The directive is a floor; national implementations differ, and we have not checked yours.
- What your supplier charges. The market price is the first term of a sum, and the rest of it is in your terms — what the whole formula looks like is a separate article.
Where to read more
- Spot price, all-in price, your price — what the market price turns into on your bill.
- Where the hub gets the price — which public sources publish it, and for which zones.
- Where your price comes from — the device reference, including the hourly-mean setting this article is about.