Cancelling a mobile contract: Deadlines, the cancellation button, number porting

Spring is traditionally the time for decluttering – basement, wardrobe, subscription collection. Yet many people still put off dealing with their mobile plan. Too complicated, too much paperwork, and in the end you're unreachable for three days? These worries are from a different era. Cancelling a mobile plan today is done in ten minutes, the phone number moves over without any dead zone, and the deadlines are more consumer-friendly than ever. You just need to know the right order to do things in.

That's why this article is laid out as a timeline – from six weeks before your desired date to the day after.

First: which deadline applies to you?

The legal situation is pleasantly clear-cut. Since the TKG reform of December 2021: after the minimum term expires (usually 24 months), your contract no longer automatically extends for another year, but instead continues for an indefinite period – and can then be cancelled at any time with one month's notice. The notorious situation of "missed it by one day, trapped for twelve months" no longer exists.

In concrete terms: if you cancel on 23 March, you're out by 23 April. If you're still within the minimum term, the cancellation takes effect at its end – provided it's submitted at least one month in advance. You can find out when your minimum term ends in the customer portal, in the order confirmation, or on your bill.

Two special cases deserve a mention: if there's a price increase or a contract change to your disadvantage, you have a special right of termination, usually with a three-month response window from the date of notification. And if you permanently have no network coverage at your place of residence, you can negotiate an extraordinary termination – though this is more difficult and requires documentation.

Six weeks before: sort out your successor plan

Cancelling without a backup plan is like moving out without a new place to live. So compare first, then cancel. Take half an hour and work through your usage profile: how many GB do you really need, which network works well at the places you go every day, fixed term or flexible? If you're still unsure about that last question, our comparison prepaid vs. contract can help. The market overview is provided by the plan comparison, and if two candidates remain, compare them head-to-head in the Side-by-Side Comparison side-by-side comparison.

One tip that can be worth real money: some providers suddenly make surprisingly good win-back offers to existing customers after they cancel. You shouldn't count on this – but if the offer does come, weigh it soberly against the new plan. Supposed loyalty discounts often turn out to be a bad deal once you do the maths.

Five weeks before: cancel – ideally via the button

Since July 2022, every provider has been required to provide a cancellation button on its website – easy to find, usually labelled "Cancel contracts here". Going through the button has a decisive advantage: the provider must confirm receipt of your cancellation electronically right away. This confirmation is your proof. Save it, don't delete it.

Calling the hotline works in theory too, but in practice, please don't: what was discussed on the phone is hard to prove later – and from experience, such a call tends to turn into a win-back loop where you're offered a new deal three times before the cancellation is even logged. The button doesn't argue with you.

One important point when cancelling: tick the box, or note in writing, that you want to keep your port your number number. This doesn't commit the provider to anything new, but it clearly signals that a number porting request will follow shortly.

Four weeks before: order the new plan with porting

Now you order the new plan and specify during the ordering process: port number, previous provider, number, name exactly as registered with your old provider. This last point is the most common stumbling block – if your old provider has "Max Mustermann" on file and you enter "M. Mustermann" with the new one, the porting will fail. So check beforehand in your old customer account how you're registered there.

The providers handle the rest between themselves. The number usually switches over at the end of the contract, though with many providers it can happen earlier on request. The switchover day itself is unspectacular: a few hours during which the number moves, announced by text message. Being "unreachable for three days" simply isn't a thing anymore.

By the way: porting still works even if you forgot to arrange it when cancelling – you can bring your old number over to a new provider for up to 123 days after the contract ends. And the cost? The old provider is allowed to charge a small fee of up to €6.82 for porting, though many now waive it. On the other hand, plenty of new providers credit you with a switching bonus for bringing your number along. So on balance, porting often actually earns you money.

Two special cases: right of withdrawal and prepaid

If you've just signed a new contract and already regret it: for contracts concluded online or by phone, you have a 14-day right of withdrawal. This isn't a cancellation – it retroactively undoes the contract as if it never happened, without giving a reason, informally in text form. An email is enough, and the date the contract was concluded counts. So if you notice after three days that the much-praised network doesn't actually exist in your own bedroom, you don't have to sit out 24 months.

And prepaid? Formally, there's often nothing to cancel at all – the SIM simply expires once you stop topping it up. Still, two things are worth doing: first, port your number in good time before the provider deactivates the inactive SIM. Second, have your remaining balance paid out – you're entitled to this, even though some providers hide the process as if it were a state secret. An informal letter with your IBAN and customer number is enough – if needed, the consumer advice centre can help with a template letter.

After switching: three things people often forget

• Check the final bill. Remaining balance, pro-rata base fee, any amounts overpaid – the old provider has to settle everything properly. If they don't do it on their own, request it in writing.
• Keep an eye on the direct debit authorisation. After the final invoice, nothing more should be debited. If it is: reverse the direct debit and ask what happened.
• Activate your new SIM or eSIM in good time. How the digital process works and where it can go wrong is covered in our eSIM guide.

That leaves the big question: is all this effort worth it? Almost always. If you haven't touched your plan in four or five years, chances are you're paying significantly more per gigabyte than the market demands – old contracts don't automatically get cheaper, just older. An hour of effort, spread over six weeks, against years of overpriced base fees: this trade-off practically always works out in your favour. And if you're unsure which plan fits your profile while comparing – via our free callback we'll go through it together.