In case you are not aware, eight mobile has enabled this feature that allow you to port in your existing M1 or Singtel prepaid numbers over to eight postpaid plans. (Starhub is excluded).

During sign up, select Use current number. Key in your mobile number, select current service provider and current billing type.

After that, go through the verification of your NRIC through SINGPASS, filling in your collection method , contact and payment mode. Once these steps are done, porting will begin when your eSIM or SIM (collected) is activated. The porting will take place late at night and should be done past midnight.