Can other account members add their checking account information, to pay their portion of my bill, without affecting the automatic payments I have set up?
You can have multiple payment accounts saved, however it will always deduct any balance due from the primary account you have set up with the auto pay. So if you wanted someone to pay a portion of the bill, be sure thats done manually well in advance of the auto pay date. This link will show you how to add payment methods to your account. https://www.verizon.com/support/knowledge-base-301813/
-Meg
As far as I know, you can only have one payment method attached to your account for autopay, so no, you can't have multiple bank accounts being used for one group bill.