If the prepaid card is canceled, the number does not need to be released. Your new provider orders the porting at the end of the contract.

Hello ​@Sms0712,

welcome to our o2 Community.

I see that Bumer has already been able to help you. If you have already canceled, your new provider can request the number from us and start the porting process.

If you have any further questions, please let us know.

Kind regards, Lea