Just need confirmation that bill pay disputes would follow the REG E dispute process, correct?

Sure. If they meet the definition of "Unauthorized electronic fund transfer" in §1005.2(m).

that's what I thought.. thanks!

Following up on this old thread - is this specific to the bank's bill pay service offered through online banking? And does it matter how the item clears the customer's account? For example, our bill pay provider has the right (per contract) to pay the bill electronically, by paper draft, or by corporate check (drawn on the bill pay provider's account). Clearly an ACH transaction is going to be a Reg E item, but will the paper draft (item clears the customer's account as a check) also be something we need to handle as Reg E if there is a dispute? And for items paid by corporate check as well?

There is commentary in Reg E that speaks to bill pay scenarios but it is rather confusing.

I'm assuming (hoping) Reg E would not be applicable to situations where the customer disputes a paper draft that was NOT created through bank's bill pay provider. Those would be remotely created check disputes.