We have a gocardless account, however it's not been used...
Why not?
Where ever possible we take payment in advance, or at least a deposit. Larger companies will do so by BACS, occasionally by cheque, whilst smaller customers will do so by credit/debit card. Most of our purchases are 'occasional'
Credit account holders are frequent customers, and have a proven trading history with us, so we're comfortable with invoicing and awaiting for a BACS payment.
Some of our corporate clients, well, they just wont entertain a direct debit payment.
With gocardless, it requires the customer to register for an account too, which may put some off, entering your bank details into a website you've never heard of???