Job offer won't accept my proof of address

Hi all,

I've passed the interview stage and now being processed through onboarding.

I've sent my passport, bank statement, and official proof of n.i number letter
(Which has the same address as bank statement) . Recruitment has stated the n.i letter isn't proof of address..

The only other proof of address I have is an electoral roll letter and money I owe hmrc.

I need to know:

1. Legally, is the n.i number not proof of address as I've used it for a previous job and had no issues.

2. Am I able to use the money I owe hmrc letter, or the electoral roll letter as proof of address?

Also, I don't pay any phone bills or council tax as I live with parents.

Any letter from HMRC or your local council is generally accepted.