Hi @Kevind27,
Welcome to TPG Community! Yes, your current sim will work until porting is completed. Once you request to activate your TPG SIM Card, you'll receive an SMS with a security code to authorise to bring your mobile number to TPG. You'll need to reply to the SMS with the code.
Please keep your current SIM Card in your mobile phone so that you can receive this SMS.
For more info, you head over to this link:
Porting or Transferring your Mobile Number to TPG
https://community.tpg.com.au/t5/SIM-Only-Plans/Porting-or-Transferring-your-Mobile-Number-to-TPG/m-p...
If you need furher assistance, do not hesitate to let us know,
Regards,
Daisy_Dhen
