Does anyone used bottomline for transferring UK BACS file between Peoplesoft and The Royal Bank of S

We are working on Peoplesoft account payable implementation for UK division. The account share service team suggests to use Bottomline Technologies for BACS file transfer. The company bank is the Royal Bank of Scotland. For all our domestic payments, Peoplesoft generates ACH file and send to bank side directly. Does anyone has any experience with UK bank file transfer? I’d like to understand why do we need use the middle man for file transfer.

Thanks!