Explainer
Fixed or spot electricity price: what fixation means
A fixed price and a spot price decide who carries the risk of market swings. This guide is for anyone choosing a contract: what fixation guarantees and what not, how a dynamic price differs and which contract terms are worth reading.
Prepared by the Banbosh Studio editors with AI from the comparison's data; first published 15 October 2026. Facts checked on 15 October 2026 against the 7 sources listed at the end. Text last updated 15 October 2026.
The short answer
A fixed price gives certainty of the unit price for the agreed period; a dynamic price passes market swings on to you. ERÚ says which type pays off cannot be told in advance, because price swings cannot be predicted. Decide by how much uncertainty you can bear.
- This applies to households as consumers; businesses have some deadlines different.
- Fixation protects against a price rise by the supplier, not against a change of the regulated part or taxes.
Three ways a price may be agreed
- Type of price: Fixed price (set for a period)
- What changes during the contract: The commercial part does not changeWho carries the risk: The supplier bears a market rise; you do not gain if the market falls
- Type of price: No fixation, with a right to change
- What changes during the contract: The supplier may raise the price with 30 days' noticeWho carries the risk: Shared; you may terminate
- Type of price: Dynamic (spot) price
- What changes during the contract: The price follows short-term marketsWho carries the risk: You
Decision flow: fixed or dynamic price
Do you want to know the supplier's unit price in advance for the whole agreed period?
Yes → Choose a fixed price. Check the length of fixation, the penalty and the renewal rules.
Do you have interval metering at the supply point and can you bear price swings?
Yes → A dynamic price is an option; the supplier must explain its benefits and risks to you in writing beforehand.
Do you lack interval metering?
Yes → A dynamic-price contract would not take effect under the law until you have it.
No → Compare offers by contract terms, not only by price.
What a fixed price is and what it guarantees
According to ERÚ a fixed price is a price set for a given period. If it is in your contract the supplier cannot raise it unilaterally during that time. If you have no fixed price and the supplier reserved the right to raise the price or change other terms unilaterally, it must announce the change at least 30 days ahead, verifiably and personally.
Publishing it on the website is not enough.
If the change is announced properly and you disagree, you can terminate the contract at the latest on the 10th day before the announced date. If it is not announced properly, the change has no legal effect and the original price stays. That is not a reason to terminate.
Of 90 household products in our comparison, 49 have a fixed price.
Products of the official price lists checked on 10/8/2026 or later, each counted once whatever area it was read for. A spot or formula price has no fixed number, so we never rank it.
The cheapest fixed price comes to CZK 17,163 a year, the cheapest price without fixation to CZK 18,124.
Orange: the cheapest fixed price, blue: the cheapest price the supplier may change, per distribution area. Rate D02d, 2.5 MWh a year, breaker 3x25 A, VAT included; price lists checked on 10/8/2026 or later. An estimate, not a bill.
What fixation does not guarantee
Fixation concerns the unregulated part of the price, which the supplier sets. The regulated part changes every year under an ERÚ price decision and affects all suppliers; ERÚ states that this change is not a reason to end the contract. Taxes may change in the same way.
The guide on reading a bill shows how the price is split.
Fixation also says nothing about the market price when it ends. According to ERÚ it cannot be clearly said whether shorter or longer fixation, or a fixed-term contract for one, two or three years, pays off, because price swings cannot be predicted. We therefore treat any estimate of savings as an estimate, not a guarantee.
Dynamic (spot) price
Since 2024 the Energy Act defines a dynamic price as one that changes during the contract with changes in the price of electricity or gas on short-term markets. Such contracts used to be called spot. The price follows a formula known in advance and keeps moving, so a rise is usually not announced.
Before the contract the supplier must give you written information on how the price is set, on the benefits and risks, especially the risk of extreme price swings, and tell you that supply can start only with interval metering. A contract with a consumer does not take effect before the supply point has such metering. A consumer can terminate it at any time with 1 month's notice starting on the first day of the month after the notice is delivered.
Contract terms worth reading
- Duration: an indefinite-term contract can be terminated at any time, usually with three months' notice from the first day of the next month; a fixed-term contract normally runs to the end of the agreed period.
- Penalty for early termination: ERÚ states it may be fixed or depend on the months left; find it before you sign.
- Automatic renewal: at least 30 days before it the supplier must announce the price, payment terms, penalty and the renewal period; you can terminate up to the 20th day before the end of the agreed period. If no notice is sent, the contract counts as indefinite after renewal.
- Notice of changes: a change of price or terms must be announced verifiably and personally at least 30 days ahead.
- Supplier hedging index: under a fixed-price contract you can terminate without penalty if the published hedging index is below 70 % or the supplier does not publish it.
Who it is for
- You are choosing a contract and do not know what fixation for one, two or three years means.
- You are drawn to spot-price offers and want to know their terms.
- You have a fixed-term contract and its end or renewal is near.
Watch out for
- A contract without a fixed price but with the supplier's right to raise it: the supplier must announce a rise at least 30 days ahead, verifiably and personally.
- A dynamic price does not start until the supply point has interval metering, which households usually do not have.
- Ending a fixed-term contract early may mean a contractual penalty; without one only in exceptional cases set by law.
Frequently asked questions
- Is fixation always better than a variable price?
- That cannot be told in advance. ERÚ says price swings cannot be predicted, so it cannot be clearly said whether shorter or longer fixation pays off.
- Can the supplier raise the price during fixation?
- If your contract has a fixed price, the supplier cannot raise it unilaterally during the agreed period. Without a fixed price and with a reserved right to change, it must announce a change 30 days ahead.
- What is a spot price?
- The law calls it a dynamic price: it changes with short-term electricity or gas markets. The contract needs interval metering at the supply point.
- How do I terminate a dynamic-price contract?
- A consumer can terminate it at any time with 1 month's notice starting on the first day of the month after the notice reaches the supplier.
- What is contract renewal?
- An automatic extension of the contract if neither side objects. The supplier must announce it at least 30 days ahead and you can terminate up to the 20th day before the end of the agreed period.