Bacs in the UK will alert the account holder that a debit has been set up, but to set it up just requires knowing the sort code (routing number) and bank account number. Much like ACH.
The account owner can at any time go in and cancel that mandate, but they do not have to pre-approve it have it set up.
The account owner can at any time go in and cancel that mandate, but they do not have to pre-approve it have it set up.