You will always be able to take your old number with you
No sooner than 120 days and no later than 60 days before the contract with your old provider runs out, you can register to transfer your number to Sunrise, a process referred to as number porting. As soon as your old subscription ends, your new subscription with Sunrise starts. You will not be charged any fees.
If you cancel the contract with your old provider prematurely, it will take at least 10 business days to port your number. Once this is complete, you can make calls with Sunrise using your current number. You will, however, have to pay your old provider a penalty fee for the remaining contract duration.
Just sign twice and the new subscription with the old number is yours
If you purchase your new contract on Sunrise.ch, you will be sent an authorization form for mobile number porting in the mail together with the SIM card and, if applicable, a new mobile phone. Sign both this form and the new contract and hand them right back to the mailman.
Sunrise will take care of everything else for you – at no additional charge. The contract with your old provider will be cancelled automatically at the end of the contract. From this point forward your Sunrise SIM card will be activated, meaning that you remain reachable at the same number without interruption.
If you purchase your new contract at a Sunrise Shop, you can sign the porting form right then and there. You will then get a new SIM card, which will receive your current number when it is ported.
If you have a prepaid subscription, switching is even easier: Simply send a free SMS to the number 499 with the text "yes".