Not received child UTR

Hi, I definitely need to register my 7 year old for self assessment for income tax from property. Need a UTR. Filled out paper form SA1 and sent off twice in the last year. Last one on 30 November because I had not received it after the first one for 5 months and called up and was advised to resubmit. But have not received the UTR yet. Not sure how long to wait now or if I fill out another paper form? Can't do anything online as not allowed NI number until 16. Am I missing something? Any advice? The HMRC helpline said they could not help me until a record is set up with a UTR, but no way to contact the Department to ask them for advice. Thank you

Hi ChildIncomeTax,
The SA1 submitted 30 November 2023 should have been reviewed by now.
If you have still not received the UTR I would advise to resubmit the registration with a covering letter to review.
Unfortunately as no national insurance number we would not be able to reivew over the telephone or webchat.  
Thank you.