Kel

I've received a letter saying I have an overdue payment demand for a simple assessment amount. I've logged in to check the details and pay if legit and I can't find any more detail. The reference on the letter doesn't work as its supposed to begin with an x. I never got the previous letter (pa302) so how do I find this information? I can't seem to find a way to request a copy of this previous letter. I'm completely baffled on how to proceed here.

Looking for some info for how to sort this out. My surname has changed twice and has not been updated yet. Once by marriage, then by deed poll after divorce. My name is not the same after divorce. E.g, j smith, married and changed to to j jones, then divorced and changed by deed poll to j baker. I have also moved house twice. I'm not able to log in to the government gateway as the ID isn't accepted as correct. I have a new passport coming soon with my correct name, driving licence with new name and address, national insurance number. How can I resolve this?