The requirements, in full

Every device has to clear three general conditions first: it must have been sold by T-Mobile, it must not be reported lost, stolen or blocked, and the account it sits on must be in good standing. Then the postpaid or prepaid rules apply on top.

Postpaid

• The device must have been active on the T-Mobile network for at least 40 days on the requesting line.
• If it was financed or leased through T-Mobile, every payment must be satisfied and the device paid in full.
• If the account has been canceled, the balance must be zero.

Prepaid

• At least 365 days must have passed since the device was activated on the T-Mobile network.
• Under 365 days, there is a shortcut: the prepaid account must have taken more than $100 in refills during that period for each active line, and more than 14 days must have passed since purchase.
• No more than two device unlocks may have been completed per line of service in the last 12 months.

You do not submit a request

This is where people lose weeks. T-Mobile automatically and remotely unlocks an eligible device within two business days — there is no form, no code, and no phone call required. You can watch the status in your T-Mobile account or the T-Life app.

Some handsets cannot be unlocked remotely. In those cases T-Mobile sends a notification to the device within two business days of it becoming eligible, with the steps to finish the job manually. If neither the unlock nor the notification arrives, that is the point at which contacting support is useful.

Two practical notes if you end up doing it by hand: the unlock has to be applied while the phone is connected to a mobile network rather than Wi-Fi, and a rooted device will not run the unlock app at all.

How to tell whether your phone is actually locked

Do this before you request anything — a phone bought secondhand or brought from elsewhere may never have been locked at all.

• iPhone — Settings, then General, then About. Scroll to Carrier Lock. "No SIM restrictions" means unlocked; "SIM locked" means locked.
• Samsung released before September 2025 — Settings, About phone, Software information, then look at Service provider software version.
• Samsung released after September 2025 — Settings, Connections, More connection settings, then Network lock status.
• Any phone — put in a SIM from another carrier. If it connects, the phone is unlocked. This is the only test that cannot be misread.

Military deployment

Deployed military personnel who are customers in good standing can have devices unlocked on provision of overseas orders, outside the normal timeline. Contact T-Mobile directly with the paperwork rather than waiting for the automatic process.

The cases that catch people out

• A phone T-Mobile did not sell cannot be unlocked by T-Mobile at all — you need the carrier, manufacturer or retailer that sold it.
• Former UScellular customers follow the separate UScellular unlocking policy, not this one.
• T-Mobile may ask for proof of purchase, and states it can deny a request it believes is an attempt to defraud the company.
• Prepaid customers who have already unlocked two phones on a line in the past year have to wait, regardless of how long the third has been active.

Once it is unlocked

An unlocked phone is worth more and costs less to run. It also removes the main reason people stay on a plan they have outgrown. Two things are worth knowing: check the phone supports the bands your new carrier uses before you switch, because unlocked does not mean fully compatible, and re-pick your plan rather than porting your old one across — data pricing has changed a great deal, and most people are paying for far more than they use.