Or you might need to enter an unlock code provided by your current cell phone company before you can install a new SIM card.

DON’T MISS: You can unlock your iPhone 6 for free on any carrier starting this week – here’s how In order to unlock a device, you first have to be familiar with your carrier’s requirements ...

Note: For postpaid and prepaid phones, T-Mobile may ask for proof of purchase or information about your account to grant eligibility. Does T-Mobile automatically unlock eligible phones?