I am based in the UK. The site is administered from the United States. I apologise for the confusion.
I presume that you bought the new car and because you never got the V5 for whatever reason, you never thought to change the address of the registered keeper when you moved.
I’m going to be brutally honest with you and tell you that I think that defence is likely to fail because you had something which is much bigger, the car, you know that you have to change the address when you move and that applies not only to vehicles but also your driving licence, bank statements, et cetera.
Legally, it is good service if it has gone to your last known address and if you don’t get it because you didn’t update the system, whatever the reason, that defence would fail.
I’m sorry, I know it’s not the answer you wanted but that is my view.
Does that answer the question?
Can I answer any specific points arising from this?
Please do not forget to use the rating service to rate my answer positively, if you don’t rate it positively, then I don’t get paid.
You may get the impression that the thread closes after rating, but it does not, it remains open and we can still exchange emails if anything needs clarification.