Transferring phone number and device from T-Mobile to T-Mobile?

mind adding a bit to this? from one TMO account to another TMO account? the primary account holder of the one account would need to give permission to that number to allow it to be moved to another account..the PAH for the other account will then need to allow that number to be added to their account and it would need to be transferred. are both account holders by chance in the same town?