Need to submit SA100 SA105 SA109 SA110 as a NRL

I am a foreigner, have a small property in UK that is being rented. I applied for a NRL several years ago and signed a form Authorising my agent to do the taxes. Those services can no longer be provided to me as I'm a resident of Russia. I filled in those forms SA100 SA105 SA109 SA110 in a software that is approved by HMRC but Authentication Failure happens when I try to submit. I can't Log in using my Goverment Gataway User ID (don't have a National Insurance number) - the system doesn't seem to verify my data. Wrote to Support but it's been 2 weeks and no answer received. I have a UTR and would like to file the forms online. How can I proceed?

Also requested access to Self-Assessment using UTR The note on the web side says I will receive an activation code "in the POST" within 7 days I just wonder what address HMRC might use since I don't live in UK and never have...

Hi Voblafish,
Thank you for your question.
You are best advised to directly speak to the Non Resident landlord helpline on this matter:
Tel 44 300 322 9433
Non-UK resident landlords
Thank you. 

Hi Voblafish,

HMRC would use the address you provided when registering for self assessment.

Thank you

 

I didn't use any address while registering for Self Assessment, only the UTR. I am supposed to receive some code at some address and later somehow use it) I guess I will print the forms, sign and send them by post, understanding there will be a late filing fee involved. The online system is very hard to use if you are not a resident of UK.