If your current device payment contract has expired, and you’ve paid for your phone in full, there’s no fee to upgrade to a new phone (other than the cost of your new phone and plan). But if your current phone is still in contract, you’ll be charged for the remaining cost of your phone if you want to upgrade to a new phone on your existing mobile service.
You can check your device payment contract end date, and any charges that may apply to upgrade your phone, in the My Telstra app. Sign in to My Telstra, select the mobile number of the phone that you want to upgrade, and follow the prompts to view your plan details.
Sign in to My Telstra