Cancel a mobile contract: notice, form and your number

The safest way to cancel a mobile phone contract in Germany is in text form – by letter, by email or via the cancellation button on the provider's website – no later than one month before the minimum term ends. If the minimum term is already over, you can cancel at any time with one month's notice. You can keep your phone number free of charge. This guide explains which notice period applies to your contract, what your cancellation letter must contain, how number porting works step by step and when you have a special right of termination (Sonderkündigungsrecht).

Which notice period applies to my mobile contract?

For most mobile contracts, the rule is simple: during the minimum term, you cancel to the end of that term; after it, you can cancel at any time with one month's notice. Which situation applies to you depends on when you signed the contract and whether the first term has already expired.

Since December 2021, the German Telecommunications Act (Telekommunikationsgesetz, TKG) has set new rules for contract terms. Under Section 56 TKG, the initial minimum term of a consumer contract may not exceed 24 months. If the contract is then renewed automatically, you can cancel it at any time with one month's notice. The old automatic renewal for a whole extra year no longer exists for consumers.

The minimum term (Mindestlaufzeit) is the period during which you are firmly bound to the contract, usually 24 months and sometimes 12 months. Before you sign, providers must also offer you a contract with a term of no more than 12 months. You will find the end date of your minimum term in the contract summary, on your bill or in your online customer account. Important: the term usually starts when the SIM card is activated, not on the day you signed.

Your situation	Notice period	End of contract
Contract still within its minimum term (e.g. 24 months)	usually one month before the minimum term ends	at the end of the minimum term
Minimum term over, contract has been renewed	one month	one month after your cancellation arrives
Contract with no minimum term (cancellable monthly)	as stated in the contract, often one month or less	as stated in the contract
Prepaid card	as stated in the contract, often short	as stated in the contract
One-sided change to the contract, e.g. a price increase	no notice period, cancel within three months of being informed	without notice

An example: your 24-month contract was activated on 15 March 2025. The minimum term ends on 14 March 2027. For the contract to end exactly then, your cancellation must reach the provider by mid-February 2027 at the latest. If you miss this date, it is no longer a big problem: the contract continues, but from then on you can cancel it every month with one month's notice.

How do I cancel correctly – by letter, email or cancellation button?

You can cancel by letter, by email or via the cancellation button on the website; the only thing that matters is that you can later prove it arrived. The provider may not demand a stricter form than text form in its terms and conditions.

Text form means a readable statement that shows who is making it – a handwritten signature is not required. Under Section 309 No. 13 of the German Civil Code (BGB), clauses requiring a stricter form are invalid in consumer contracts. So an email is enough, and so is a letter.

If you were able to sign the contract online, the provider has had to offer a clearly visible "cancel contracts here" button (Verträge hier kündigen) on its website since July 2022. This is set out in Section 312k BGB. Once you submit, the provider must confirm your cancellation electronically straight away, with date and time. Save this confirmation or take a screenshot.

Which route is the safest? The cancellation button automatically creates time-stamped proof. A registered letter with proof of delivery (Einschreiben mit Rückschein) proves receipt on paper. A simple email is convenient, but you should ask for an acknowledgement of receipt. If no cancellation confirmation arrives within about two weeks, follow up – ideally in writing again.

Calling the hotline, on the other hand, is not a good choice. A phone conversation is hard to prove later, and a cancellation can quickly turn into a "contract extension with a discount".

What must my cancellation letter contain?

Your cancellation should include your name, address, phone number, customer or contract number and a sentence saying that you are cancelling at the earliest possible date. With this information, the provider can clearly identify your contract.

Two additions are also helpful: a request for written confirmation of the cancellation with the exact end date and, if you wish, a note that you want to keep your phone number. If you do not want a call back, say so explicitly as well. The consumer advice centre (Verbraucherzentrale) recommends the same essential details and explains how to keep track of deadlines.

You do not need a reason for an ordinary cancellation. You do not have to explain why you are leaving. Only when using a special right of termination do you state the reason, such as the price increase or the proven shortfall in performance.

Make sure the details match those in the contract. If the contract is in the name of your spouse or a parent, that person must cancel or sign a power of attorney. This also applies if you have been using the card yourself for years.

How can I keep my phone number?

To keep your phone number, you apply to the new provider, which then arranges the switch with the old provider. All you do yourself is tell the old provider that you want to keep your number.

Experts call this number porting. The process is governed by Section 59 TKG. Under this rule, the receiving provider carries out the switch, and both companies are obliged to cooperate. Here is how to proceed:

1. Cancel your old contract and state that you want to keep your phone number. For mobile numbers, you can request porting even before the contract ends.
2. Sign the new contract and state there that you want to keep your existing number. The new provider needs your number, the name of your old provider and your contract details.
3. Check that your name, date of birth and address are written in the new contract exactly as in the old one. Small differences, such as a missing middle name, are the most common reason why porting fails.
4. The new provider requests the porting and tells you the switch date. Until then, your old SIM card stays active.
5. On the switch date, insert the new SIM card. The changeover usually takes only a few hours. After that, your contacts can reach you on the same number as usual.

Do not miss the right moment entirely: under Section 59 TKG, you can still request number porting up to one month after the contract ends. After that, the old provider may reassign the number.

How much does number porting cost and how long does it take?

Number porting is free, and the number must work with the new provider no later than the working day after the agreed date. Section 59 TKG has required both since December 2021.

Providers used to charge up to 30 euros for this. In 2020 the Federal Network Agency (Bundesnetzagentur) first capped the fee at 6.82 euros; under the new Telecommunications Act, end customers may no longer be charged any direct fees for porting at all. If a porting fee still appears on your final bill, object in writing.

If the switch does not happen on time, you are entitled to compensation: you can claim 10 euros from the responsible provider for each day of delay. In addition, your service may not be interrupted for more than one working day when you switch providers.

Still, plan in some buffer. If you are expecting important calls, for example from your employer or your doctor, it is best not to set the switch date on a Friday or just before a public holiday.

When do I have a special right of termination?

You have a special right of termination mainly when the provider changes the contract to your disadvantage on its own or permanently delivers much less than agreed. In that case, you can leave the contract even during the minimum term.

Price increase or other contract change: If the provider changes the terms on its own, you can cancel without notice and free of charge under Section 57 TKG. You have three months to do so, counted from when you receive the notification. The right only lapses if the change is solely to your benefit, purely administrative or required by law. So read letters and emails from your provider carefully, even if they look like advertising.

Mobile internet that is too slow: If your tariff permanently fails to reach the promised speed, you can reduce your payments or terminate the contract early. In April 2026 the Federal Network Agency set out how to prove this for mobile: you need 30 measurements over five calendar days. In densely populated areas, there is a significant shortfall if on at least three days not even 25 percent of the estimated maximum speed is reached. You present the measurement log to your provider.

Moving house: If you move within Germany, your mobile contract normally continues because mobile coverage is available almost everywhere. The special right of termination under Section 60 TKG only applies if the agreed service is not offered at your new home – which mostly affects DSL and landlines. If you move abroad, the law does not give you a fixed right. Many providers let you leave earlier with proof, such as your deregistration certificate (Abmeldebescheinigung). Ask in writing.

Missing cancellation button: If a provider with whom you could sign up online does not offer a working cancellation button, Section 312k BGB allows you to cancel at any time without notice.

By the way, you do not gain a special right of termination simply because you have found a cheaper tariff or your smartphone is broken. In that case, the normal notice period applies.

What should I do if the provider calls after I cancel?

A call after your cancellation is a win-back offer, and you do not have to listen or agree to anything. Your written cancellation remains valid as long as you do not withdraw it yourself.

Many providers get in touch once your cancellation arrives, with an offer: more data, a discount on the monthly fee or a new smartphone. This can be worthwhile – but only if you have the offer in writing and can compare it with other tariffs. On the phone, "I'll think about it" can quickly turn into a new 24-month minimum term.

Some providers also call the letter they received a "cancellation note" (Kündigungsvormerkung). What this means is that your cancellation has been registered and the contract ends on the date stated. Check exactly this date in the confirmation. If it shows a later date than you are entitled to under the notice period, object in writing.

If you do not want any calls, write in your cancellation: "Please do not contact me by phone." And if you do want to accept an offer, have it sent to you by email before you agree.

How do I cancel a prepaid contract?

You cancel a prepaid contract in writing, just like a fixed-term contract, usually with a much shorter notice period. Prepaid cards generally have no minimum term; the notice period is in the contract terms.

Simply not topping up is not always enough: the card often stays active for months, and until then your phone number remains tied to this contract. If you want to keep the number, cancel actively and request porting – it is free for prepaid too.

Remember your remaining credit. Use it up before switching, or request in your cancellation letter that it be paid out to your bank account and include your IBAN.

What happens to smartphone instalments and extra SIM cards?

When you cancel, you need to keep a separate eye on any smartphone you bought with the contract and on extra SIM cards, because they are often tied to their own terms or instalment plans. Cancelling the tariff does not automatically end all other obligations.

If you paid for the smartphone with a separate instalment agreement, the instalments usually continue until the end, even if the tariff has already been cancelled. Check your documents to see whether the device and the tariff are in one contract or in two separate contracts.

Families with several cards should look especially closely. Extra cards, partner cards or children's cards are often linked to the main contract. If you cancel the main contract, the extra cards may end with it – along with their phone numbers, unless you request porting for each card separately. For a family of four with four cards, that means four numbers and four porting requests.

If you often call abroad, you should also check before switching whether the new tariff includes the services you are used to. Read more in our guides Ay Yildiz tariffs at a glance and When is a Turkey flat rate worth it?.

Cancel and switch your mobile contract with Connected Mobile

Cancelling, keeping your number and finding the right new tariff is not rocket science, but it is a chain of deadlines and forms where small mistakes cause a lot of trouble. This is exactly the part we take care of: we check your contract term, write the cancellation, request number porting and compare tariffs from our partners such as Vodafone, Telekom, 1&1, Otelo and Ay Yildiz. Find out more about our advice on mobile contracts, internet and energy on our home page.

All you need to bring is your latest bill and your ID. We handle the rest together with you, in German, Turkish, Kurdish or Arabic, and you keep your number. You will find more tips on contracts in our blog.

Bring your latest phone bill to our shop in Moers or Duisburg or send it via WhatsApp – we will check your notice period and take care of the switch.