I have two credit cards with the cooperative bank.
I set up standing orders for both cards with the credit card numbers as the references.
What happens though is that the first payment goes out, and any payment to either card after pays towards one card only. The payment reference is “remembered” and thus my standing order is re-written.
This appears in my app as though i have paid both cards - no problem.
Then i get both a non payment notice and charge and mark against my credit score.
I report this to Monzo, seeing as this seems to be a technical / programming issue. Attached is the response I got from Monzo.