Just had this email from gocardless, it appears that they are able to tell if you have set up the customer yourself?
Had a customer that said he wanted to go on dd but I got fed up of waiting for him to do it so I asked him to text me his account number and sort code and did it myself -
Hi Wayne,
I’m just getting in touch from GoCardless.
Your account has flagged on of our verification checks, as it appears that you are filling out the Direct Debit mandate for your customers. This is just a friendly reminder that the Direct Debit scheme rules states that customer must complete this process themselves. This verification flag will not stop any of your payments, apologies if you are not completing this form for your customers. It would be really helpful if you can let mw know how you add your customers to GoCardless.