To separate phone lines on T-Mobile, you cannot use a generic "separate" button or feature; instead, the process depends entirely on your situation. For standard family plan accounts, you need to complete a Change of Responsibility (COR) to move a line to its own account, while survivors of abuse can use T-Mobile's dedicated Safe Connections Act process.
The truth about how to separate phone lines on T-Mobile
T-Mobile does not offer a one-click "separate phone lines" tool for ordinary consumer accounts. The documented path for line separation is the Safe Connections Act process, which applies only when a survivor is requesting separation of a line from a shared account after abuse or a covered act. For standard accounts, the real process is a Change of Responsibility (COR), where the current account holder authorizes the release and the receiving person passes a credit check and accepts the line into their own new or existing account.
The standard path: T-Mobile change of responsibility
To move a line from a shared T-Mobile family plan to its own account, the current account holder must authorize the release of the line. The person receiving the line then passes a credit check and accepts the line into a new or existing T-Mobile account. This process is called a Change of Responsibility (COR) and is the standard method for separating lines when both parties agree. You can keep your number during a COR, as the number transfers with the line to the new account.
The Safe Connections Act process for survivors
For survivors of abuse or a covered act, T-Mobile provides a dedicated line separation process under the Safe Connections Act. To start, contact Customer Care at 1-877-746-0909, dial 611 from a T-Mobile device, or visit a T-Mobile retail location. A line separation request must be supported by documentation, unless the survivor is in New York and the billing address on the shared account is in New York. This process is specifically designed for survivors and is the only T-Mobile-documented "line separation" feature for consumer accounts. T-Mobile TTY number 1-800-676-3777.
What you can do right now with multiple lines on one account
If your goal is not to separate billing but to use multiple lines from the same account on a single phone, you can use eSIM. T-Mobile documents how to add or move a line onto eSIM, which keeps multiple lines on one device separate. On iPhone, eSIM activation with Quick Start is available for iPhone Xs or newer running iOS 15.4 or higher. For other devices, use the T-Life app: disable SIM Protection, open the T-Life app while connected to the T-Mobile network, select the Account tab and choose the line, choose SIM transfer or activation, then Get Started, enter the IMEI, choose to activate an eSIM, enter the EID, review the change and select Activate, then respond to any interactive SMS if prompted. T-Mobile's public eSIM compatibility page lists supported phones. T-Mobile Prepaid eSIM app is documented as a way to activate new prepaid service on an iPhone or Android with eSIM. For transferring a line’s eSIM on “other devices,” T-Mobile’s current steps include disabling SIM Protection. T-Mobile’s eSIM support flow requires an eSIM-capable device, the latest software, Wi‑Fi, and, if transferring from an old iPhone, Bluetooth on plus a passcode-protected device.
Frequently Asked Questions
Can I keep my phone number when separating lines?
Yes, in most cases you can keep your number when separating lines via a Change of Responsibility. The number transfers with the line to the new account, so you do not need to get a new number.
Are there fees to separate phone lines on T-Mobile?
T-Mobile may charge a one-time fee for a Change of Responsibility, but the exact amount depends on your account and plan. Check with T-Mobile customer service for current fees associated with line separation.
What is the difference between separating an account and just getting a new line?
Separating an account moves an existing line and its number to a new account, changing billing responsibility. Getting a new line adds a fresh line with a new number to your existing account without changing billing for your current lines.
Does the Safe Connections Act process require documentation?
Can I use eSIM to have two lines from the same account on one phone?
Yes, you can use eSIM to have multiple lines from the same T-Mobile account on one device. This does not separate billing but allows you to use two numbers on one phone.
What is the difference between separating lines and porting and releasing phone numbers?
Separating lines via Change of Responsibility keeps the line on T-Mobile but moves it to a new account. Porting and releasing phone numbers moves the number to a different carrier entirely, which is a separate process from account separation.
