SO my car needs taxing and I can't do it onlne as the reg and the insurance addresses don't match any more.
SO I call the DVLA.
They advise me to go to their local office, so off I go

I explain the problem,. They give me the form to change the reg address and I also change my licence address at the same time.
Then I say, "Now can you sell me a tax disc?"
No

I say that I can do this on my home laptop with the renewal notice or my logbook (neither of which I have) and their system verifies my insurance and MOT, like.
"Our system is too old and we can't do that"

SO I can renew the tax on line from my laptop, but the DVLA CANNOT do it using their compooters. HOw does that werk??