Porting a mobile number
If porting a mobile (wireless) number, the end-user will need to ask their carrier for the Wireless Account Number, and submit this as part of your port.

This WL Account Number is different from the mobile phone number. Sometimes you can find this on the phone bill, but otherwise the account owner can contact their carrier and ask them for it.
The confirmation SMS
Section titled “The confirmation SMS”In order to port a mobile number, the losing carrier will send an SMS to the account owner, and the account owner must respond to the SMS to confirm their acceptance to release the TN.
See here for more details on port rejections.