Question about split Billing

[news]

[wireless]

I share paying internet services with my roommate. She has it set up to take the bill off her credit card automatically every month, I was curious, if I just paid the direct account as opposed to sending her the money, would it still charge the regular monthly bill amount off her credit card or if the balance was only a portion of the bill (after I pay it) will it only charge her that portion?

More...