Just to echo what people have said here. At least with Barclaycard and Tesco Bank there’s a central Account Number and Sort Code for all accounts and then the Reference is your 16 Digit Credit Card Number. Example below from Barclaycard:
http://help.barclaycard.co.uk/brochure/paying_bill/pay-my-bill
Depending on the provider, you can also pay online/over the phone with your Debit Card (Tesco Bank will only do this if you persist on the phone with your Monzo card because they suck).