Posting for traffic, really. I've just realised I haven't taxed my car (tax expired on 31/3) and have had 4 goes at doing it online, using 2 different cards. For both, it tells me that the card is invalid.
Then I had 2 goes at doing it over the phone, once with each card. The first time the call dropped, and the second it said that it's not possible to complete the transaction, although it confirmed that MOT and insurance are fine.
I can't go to the post office and do it because in my stress and panic I can't find the insurance certificate!
I'm hoping there will be someone else on here trying to do the same who can reassure me that it's a DVLA thing and not something weird to do with my car.