Trying to register for self assessment

HI there. I am trying to get a UTR and no matter what I do I fail the identity check. I suspect that the name I am registered with HMRC is different from the name on passport and driving license Buti can't seem to find a place where I can access all my information. I tried to change the name but to change the name you have to pass the identity check and it fails . I am running in circles because everything depends on the identity check and that is what is failing so I pretty much cannot get my urgently needed UTR. Can anyone please advise ? I have tried ringing 03002003300 but after a load of recordings the number hangs up. All recommendation is that I can do it all online BUT if I fail the identity check I can't do anything. Is there an address I can write to? Please do advice . I am running out of options! Thanks.

Hi Miguel JLAPT,
If you are unable to register online you can download and submit the form to register for Self Assessment.
If self employed the form will be CWF1 and if not self employed the form is a SA1
Check how to register for Self Assessment
Thank you.