Each line can be named differently. This makes it easier to identify each line when looking at line usage and EIPs. You have an account ID and each line has a personal ID. At least that's what I see on my T-Mobile Account page.
Hi, thanks for quick response.
Hmmm...as it current stands with having just one TM ID, I have named each line and easily see the names I have given to each line. In addition, I can manage both lines as I'm the primary account holder. I may be new and not fully understanding of account management yet but it seems that if that's al there is to it, seems somewhat redundant.