Contact your carrier and request an unlock
Confirm the iPhone is paid off and not under contract
Make sure the account is in good standing
Verify the iPhone is not reported lost or stolen
Check the carrier’s unlock eligibility requirements
Back up your iPhone
Insert a SIM card from the new carrier
Connect the iPhone to Wi-Fi or cellular data
Complete the unlock through the carrier’s process
Restart the iPhone if needed
If the unlock does not work, contact the carrier again