Porting Your Number in Switzerland: Checklist for Changing Mobile Plans

Do you want to change your mobile plan but keep your existing number? This is normally possible in Switzerland. For number porting in Switzerland to run smoothly, your details must be correct, your existing number must remain active and the porting form must be completed in full.

The most common problems are not caused by the change of provider itself, but by small discrepancies: an old name on the existing contract, an unreported change of address or a prepaid number that has already been cancelled. This checklist helps you avoid such delays before switching.

Most important first: do not cancel too early yourself

When porting a number, you ask the new provider to transfer your existing mobile number to its network. The new provider then forwards the request to your current provider, which checks whether the number and contract details are correct.

Do not cancel your existing mobile plan yourself too early if the porting form includes a cancellation authorisation. In many cases, the new provider handles the cancellation as part of the porting process. An additional cancellation by you can unnecessarily complicate the process, especially if dates or contract details no longer match.

Important: porting does not automatically cancel contractual obligations. Minimum terms, notice periods, outstanding device payments or other costs from the old contract may still apply. Check your current contract and latest bill first.

If you want to compare suitable offers, you can find an overview under Compare mobile plans. There you can compare the services and conditions of different providers.

Checklist: keeping your number when changing providers

Go through these points before ordering the new plan or submitting the porting form:

• Your mobile number is still active with your current provider.
• The contract is registered under your current, correct name.
• Your name, first name, date of birth and address match with both providers.
• For business connections, the company name and authorised representative are correct.
• You are using the correct contract or customer number, if the form asks for it.
• You know the notice period, minimum contract term and possible end date of your current plan.
• The porting form is completed and signed, if a signature is required.
• You have saved confirmation or a copy of your request.
• You do not remove the existing SIM or eSIM until the new provider asks you to or the switch has taken place.

1. Personal details must match exactly

Contract details are the most important aspect of porting. The current provider must be able to verify that the person requesting the transfer is authorised to use the number. Even minor discrepancies can lead to a rejection.

Pay particular attention to the following details:

What to do if your name or address has changed

If you have married, divorced or changed your name, the old provider may still have your previous name on file. The same applies after moving house. In this case, update your details with the current provider first or enter exactly the details currently stored there in the porting form.

Porting is also possible if the number is to be transferred to another person. However, this is not an ordinary port: depending on the provider, a contract transfer or separate declaration of consent may also be required. First clarify who is formally the holder of the number.

2. The number must remain active until the switch

Your number must generally still be active with the current provider when the porting request is processed. If the connection is deactivated beforehand, the number may no longer be transferable through the regular process.

This particularly affects the following situations:

• You cancel a prepaid offer or leave it unused for so long that it is deactivated.
• You cancel your plan yourself with immediate effect before the porting date is confirmed.
• You switch too quickly after moving house or changing your contract and give up the old SIM prematurely.
• The existing contract is blocked or terminated because of unpaid bills or other problems.

Prepaid offers usually do not have a standard cancellation period. Nevertheless, do not simply allow the number to expire. Request porting in good time, while the prepaid credit and number are still valid. The identification details required depend on the current and new provider.

Avoid a prolonged interruption

On the porting day, the number is technically transferred from the old to the new provider. A brief interruption to calls, SMS or mobile data may occur. Therefore, do not schedule the switch immediately before travelling, an important business appointment or a period when you must remain continuously reachable.

Keep your old SIM card or the details of your previous eSIM until porting is complete. Once the number is active on the new connection, follow the new provider’s activation instructions.

3. How the porting form works

The porting form is the basis for transferring your number. It generally includes your mobile number, details of the existing contract, information about the new plan and your consent to porting. You can often complete the request during the online ordering process; in some cases, a separate form is required.

Before submitting it, check carefully:

• Is the number to be transferred complete and correct?
• Do your name and address match the details held by the current provider?
• Did you select the desired porting date correctly, if you can choose one?
• Did you understand and correctly confirm any cancellation authorisation?
• Is the required signature included?
• Has any required proof of identity been uploaded or submitted legibly?

After ordering, you will usually receive an acknowledgement. The new provider will contact you when the porting request has been accepted, when information is missing or when a date has been set. Keep these messages. They can help if you need to follow up later.

If porting is rejected or delayed

A rejection usually does not mean that you will permanently lose your number. A formal error is often the cause. Ask the new provider for the specific reason and correct the relevant details.

Common causes include:

• The name or address does not match the existing contract.
• The number is no longer active.
• The customer number provided is incorrect or missing.
• The form is incomplete or has not been validly signed.
• The person submitting the request is not the contract holder.
• The desired switch date cannot be implemented because of contractual notice periods.

If there is a problem, contact the new provider first. It submitted the porting request and can usually tell you which detail needs to be corrected. For questions about the details on file or the contract status, contact the previous provider afterwards.

If a dispute with a telecommunications provider remains unresolved, you may, under certain conditions, contact the conciliation body Ombudscom. The Federal Office of Communications explains when this is possible and that you must first have tried to reach an agreement directly with the provider: Information from OFCOM about Ombudscom. Ombudscom documents recurring problems in telecommunications in its reports: Ombudscom reports and statistics.

After porting: points you should check

Once the switch has been completed, test your number with a short call. Also check whether you can receive SMS and use mobile data. With a new eSIM, you may first need to activate the eSIM profile or restart the device.

Then check:

• Do incoming and outgoing calls work?
• Can you send and receive SMS?
• Is the mobile data connection active?
• Was your old plan cancelled as agreed?
• Will you still receive a final bill from the previous provider?

Check the final bill carefully. It may include prorated plan charges, fees related to the contract term or outstanding instalments. After successful porting, the number belongs to the new connection, but the other elements of the old contract are not automatically transferred.

Conclusion: good preparation prevents most problems

If you want to port your number in Switzerland, three things are crucial: your contract details must match, the number must remain active until the switch and the porting form must be complete. Before submitting it, take a few minutes to compare the details with your latest bill or customer portal.

This significantly reduces the risk of rejection and usually allows you to remain reachable under the same mobile number when changing providers. To choose a new offer, use the overview of mobile plans and our advice section.