Link multiple MSISDNs to single account

Hola @wstvrgnafan4 Link multiple MSISDNs to single account could mean that your T-Mobile ID has two phone numbers added to it or that your phone number (MSISDN) is not active in DIGITS. 

Here is some information on how to Configurar y administrar tu ID de T-Mobile. You can use those steps to update the security for your T-Mobile ID by changing the password and adding two-step verification. 

Here you can learn more about DIGITS. See all the great benefits and how to manage those settings to make sure that nothing hinky is going on there. 

Hope this helps.