Can I change the service provider on my iPhone?

This sounds like the phone is currently locked to T-Mobile.

So, you would need to contact T-Mobile and ask them to unlock the phone. They "should" do this if the phone is completely paid off and your account is in good order.

We say "should" because unlocking does not happen automatically. You will have to work with T-Mobile on this. Unfortunately, all too often, users are told that their phone has been unlocked when this is not the case. It may take a few calls to get things handled.

Once the phone has been unlocked by T-Mobile, then you would be free to contact Boost Mobile and get the phone set up for their service.

Apple would not be involved at all with T-Mobile unlocking the phone or Boost Mobile setting up new service on the phone. You will be working directly with T-Mobile and Boost Mobile.....not Apple.

I understand that you may have purchased your iPhone directly from Apple and are using it on T-Mobile’s Network. You now wish to use your iPhone with Boost Mobile. This can work but only if your iPhone is not locked to T-Mobile. To check this, open Settings ➡️ General ➡️ About ➡️ Carrier Lock: Here, it should state No SIM Restrictions. If there is a Carrier Lock present, then it will list the carrier’s name here (T-Mobile). If it states, No SIM Restrictions, then you should be able to use your iPhone with Boost Mobile. You may also want to double check with T-Mobile that your iPhone is not locked to T-Mobile before you make the move to Boost.

Axel F.