Please supply a solution to this problem. I am having the extact same issue.

I have been filing online for a couple of years. Now I have to go through a process of allowing QB to file on my behalf, which I have (access code received by text and entered back into the HMRC website). However, QB fails and instructs me to check our VAT number (which has been the same for 22-years) and tells me to login again. I'm now on my fourth attempt and no further forward.

Come on Intuit, we need a solution fast.

Mike