When I tried to pay the “Fee to Pay” card I received from Royal Mail using my Monzo card, I kept getting this error:
Is this a Monzo bug or a Royal Mail one? If I had to guess I’d say that Royal Mail is enforcing SecureCode and therefore it is their problem, but I could be wrong.
That looks like their website timing out rather than anything else.
Edit. As per @anon23935806
That’s a MasterCard bug.
That page is supposed to redirect straight back to the merchant telling them that 3D Secure is not supported (Monzo are working on it).
oh, datacash, oh… 
You can stick stamps to the value on the card and send it back to pay for it. That’s so retro that it’s cool 
That’s still a bug - that page is supposed to redirect back right away, not stay there forever until the browser gives up.
Whenever you get sent to 3D Secure, 3DS says “is this card supported?” if not, kick back to the merchant and mark as successful (pretty sure the merchant doesn’t see that 3DS isn’t supported by the card). Honestly, issues with 3D Secure is why I bought my travel currency with Monzo waaaay before I switched last month, on account of just a quick redirect and back again, instead of messing with SMS verification and passwords. I will be a little bit sad when Monzo implement it, I’ll be honest.
(oh, and I bought currency because I went to Japan where the majority of places don’t take card, especially international ones)
3D Secure is on the road map to be implemented within the next 6 months.
@theshillito There’s definitely a bug here because that redirect didn’t happen. I’m not expecting 3D secure but there is no reason for the payment to fail altogether.
There is a reason for the payment to fail altogether; there’s no 3D securecode.
I’d love to hear from someone at Monzo to confirm for sure, but my understanding is that it should at least show an error or simply redirect back. A page timeout certainly isn’t ever a justifiable user experience.
It is nothing to do with Monzo. The retailer may write a good website that explains your transaction declined because your bank fails to adopt SecureCode or a poor website that just times out or errors with some meaningless code or even a blank page so you not sure if your transaction completed! It won’t get you anywhere but you can complain to the retailer and ask their customer service team to pass your comments on to their IT dept.
I have emailed Royal Mail. Not expecting anything from it but always worth reaching out.
They’ll end up with a red card in their inbox as they were out of office when gmail tried to deliver it 
I believe a team is moving onto this next week 
In this case it doesn’t look like the issue with the retailer - the timeout is occurring on a MasterCard page.