Troubleshooting devices

If your phone shows a "SIM Not Supported" or "Invalid SIM" error with your US Mobile SIM card, it may be carrier-locked. This article walks you through how to unlock your device from your previous carrier so you can use it with US Mobile.

Carrier locks on devices

Most phone manufacturers sell their phones unlocked, meaning they can be used on multiple networks. Traditional carriers, on the other hand, lock their phones — you can only use the phone on their network until you've paid off the installments and the carrier decides to unlock it.

For example, if you tried using a phone that's under contract with another carrier with a US Mobile SIM card, you'd be told the phone is locked and you'll need to contact your carrier to get it unlocked. You might see errors like "SIM Not Supported" or "Invalid SIM."

Each carrier has an unlocking policy. This article walks you through the unlocking process.

Warp-compatible devices

Most devices compatible with Warp come unlocked. If you're experiencing errors, reach out to the manufacturer's customer support to confirm the unlock status.

AT&T-locked devices (for use on Dark Star)

Go to the AT&T website and fill out their device unlock form. If you meet the requirements below, you'll get instructions in up to five business days.

1. You must be a current or former AT&T subscriber.
2. The device must be from AT&T.
3. It must not have been reported lost or stolen.
4. It must be attached to an account in good standing — one not associated with fraudulent activity.
5. It must have been active for at least 60 days with no past due or unpaid balance.
6. You've made fewer than five unlock requests in a single year.

T-Mobile-locked devices (for use on Light Speed)

Before doing anything, you must meet these requirements:

1. The device must be from T-Mobile.
2. It must not have been reported lost or stolen.
3. It must be attached to an account in good standing.
4. It must have been active for at least 40 days on the requesting line.
5. If the device is on a service contract, at least 18 consecutive monthly payments must have been made.
6. You've made fewer than two unlock requests per line in a single year.

Once you clear all those requirements, you can use the T-Mobile Mobile Device Unlock app to complete the unlocking process. You can also get your phone unlocked through a live chat with a T-Mobile customer representative, or by calling 1-800-746-0949 (or 611) from a T-Mobile device.

Cricket Wireless

Cricket Wireless requires that you meet the following requirements before they unlock your device:

1. The device you want to unlock has been active for at least six months of paid service.*
2. The device is designed for use on and is locked to Cricket's network.
3. The device has not been reported lost or stolen.
4. The device is not associated with a fraudulent account.

If your phone fits the bill, request a Cricket Mobile Device unlock via chat or phone at 1-800-274-2538, or visit your local Cricket Store. You can also request a device unlock from your account with them. Find out how.

*The six-month paid service requirement does not apply to Cricket devices purchased by Unlimited Plan customers before January 4, 2018.

Metro by T-Mobile (formerly MetroPCS)

Metro requires that your device has had active service for a minimum of 180 consecutive days from the individual phone's activation date.

Most of their non-iPhone models can be unlocked through their proprietary Device Unlock app, which comes pre-installed on eligible devices.

For all other phones, including iPhones, contact Metro Customer Service or visit a Metro Corporate Store and request the unlock code. You'll need to provide:

• The phone number of the device you're unlocking
• The name on the account
• The account billing PIN

If you're having trouble getting your device unlocked, reach out to your previous carrier and have them walk you through the process.