Gas price rise 2027: cancel, switch or stay – what owners and businesses should calculate now

The short answer

If you receive a letter announcing a gas price increase from 1 January 2027, you can cancel the contract without notice to the date of the increase, in default supply as well as in a special contract. Whether that pays off depends not on the percentage in the letter but on the new energy price, converted to your own annual consumption and compared with what a new contract costs today.

The increases are real: EnBW is raising the energy price in default and substitute supply to 13.17 cents per kilowatt hour (up 8.4 per cent), EWE from 11.01 to 12.90 cents, both gross. An overview of further default suppliers is in the news item on gas default supply 2027. What a kilowatt hour of heat costs across heating types is shown in the guide to heat costs per kilowatt hour.

By when must the supplier announce the increase?

The deadlines depend on the type of contract and the customer. For an increase on 1 January 2027, the cut-off dates are:

Contract	Notice	Latest receipt for 1.1.2027	Legal basis
Default supply (Grundversorgung)	6 weeks, public and by letter	20 November 2026	section 5(2) GasGVV
Special contract, household customer	1 month	1 December 2026	section 41(5) EnWG
Special contract, other customers (e.g. businesses above 10,000 kWh)	2 weeks	18 December 2026	section 41(5) EnWG

The letter must state the reason, conditions and extent of the change and point out the right to cancel. Exception: if only VAT changes and this is passed on unchanged, no notice is needed and no special right of termination arises (section 41(6) EnWG).

How does the special right of termination work?

You can cancel without notice to the date the increase takes effect, and no fee may be charged. Default supply can also be cancelled at any time with two weeks’ notice in text form (section 20 GasGVV).

One rule is often overlooked: if you cancel default supply and prove a new supply contract within one month of the cancellation being received, the price increase never takes effect for you (section 5(3) GasGVV). That takes the time pressure out of switching.

If the transition fails, the gas does not stop. Anyone drawing gas at low pressure without an assigned contract ends up in substitute supply (section 38 EnWG). It is a stopgap: three months at most, and the default supplier may reset its prices on the 1st and 15th of each month.

Who counts as a household customer – and what does that mean for businesses and landlords?

Under section 3 no. 57 EnWG, a household customer is anyone who buys energy mainly for their own household or uses at most 10,000 kilowatt hours a year for professional or commercial purposes. Only household customers are entitled to default supply (section 36 EnWG). A trade business with a workshop and office quickly exceeds this and then needs a special contract, with the shorter two-week notice period but the same special right of termination.

Landlords who buy gas for a central heating system and recover it through service charges must observe the principle of economic efficiency (section 556(3) German Civil Code). Accepting a significant increase without comparison risks disputes over the statement. In addition, the landlord bears part of the CO₂ costs under the tiered model, explained in the guide to the CO₂ price 2027.

What does the increase cost in euros? A worked example

Case 1, household or small business using 20,000 kilowatt hours: according to EnBW, the monthly bill rises by 17.93 euros, around 215 euros a year.

Case 2, apartment building with 10 flats and 180,000 kilowatt hours of gas a year. Here every cent on the energy price counts; the standing charge barely matters:

Change in energy price (gross)	Example	Extra cost per year
+ 1.00 cent/kWh	reference value	€1,800
+ 1.02 cents/kWh	EnBW: 8.4 % to 13.17 cents	around €1,840
+ 1.89 cents/kWh	EWE: 11.01 → 12.90 cents	€3,402

The EnBW row is calculated back from 13.17 cents and 8.4 per cent. The examples show the order of magnitude, not the tariff of an individual building: a building of this size usually buys on a special contract.

In 2027 the price contains a fixed block that no switch removes: the CO₂ price of 55 to 65 euros per tonne. With the emission factor under EBeV 2030 (around 0.181 kg CO₂ per billed kilowatt hour), that is 1.00 to 1.18 cents net or 1.18 to 1.40 cents gross per kilowatt hour, in the example building 2,132 to 2,520 euros gross a year. On top come slightly rising gas network charges, covered in the news item on network charges 2027, and from October 2027 probably a small levy for the gas reserve, which is still only a draft.

Cancel, switch or stay: when does what pay off?

Switching only saves money if the new offer is cheaper over its term than the increased tariff. In 2026 that is not a given, because new-customer tariffs reflect higher wholesale prices faster than default supply, which is procured long term. That is why the comparison in euros per year at your own consumption is the only reliable measure.

For fixed-price offers: a long commitment protects against further increases but locks in today’s high level if prices fall. Which components a price guarantee covers and which (such as taxes and levies) may still be passed on is set out in the contract and should be read before signing. Anyone wanting to reduce gas dependence in the long run should model the alternatives against the European CO₂ price from 2028, which replaces the national price corridor.

“A price letter is no reason to panic, it is a deadline. Anyone who reads it, works it out in euros per year and decides within the notice period will pay in 2027 only the price they deliberately chose.” — Pedram Dadgar

What to do now

1. Check your post for price letters until the end of November, and for businesses until mid-December; note the effective date.
2. Convert the new energy price and standing charge into euros per year using the consumption from your last annual bill.
3. Obtain at least two offers with short and long terms and do the same calculation; for fixed prices, check the scope of the guarantee.
4. When leaving default supply, prove the new contract within one month of cancelling so the increase does not apply.
5. Landlords document the price comparison for the service charge statement and adjust tenants’ advance payments in good time.
6. Show the 2027 CO₂ share separately and model the heating alternative for the period from 2028.