Registered via post but no UTR received over one month

Dear HMRC colleague We posted a hard copy application of the SA form to register for self assessment on the 8th of August to obtain the UTR number for the first time. We have not heard via letter or email whether the application was received, or any notification with a UTR number. The deadline for registering is the 5th of October - we have no proof of postage (It was a first class stamp). We have no information whether HMRC has received our application. I have tried calling the 0300 200 3311 lines several times to speak to someone. Should we send in another form, this time with proof of postage? We cannot register online as the system does not allow any options to upload the P60 (we only have the passport as the online document, no drivers licence etc) Many thanks, RBSB

Hi,
If you have submitted a registration for Self Assessment and have not yet received the UTR then you wil need to contact HMRC.
to review the submission.
Self Assessment: general enquiries
Thank you.