Date of Birth Incorrect in the system

Dear HMRC team, I was having issues confirming my identity when trying to reach my personal tax account. After some communications, it turned out that my date of birth is not correct in your system. Now I need to send you certified documents to make this correct. The most practical method seems to be the Post Office certification method because the banks are not doing this anymore and I don't know anyone from the few listed occupations in gov.uk's link for who can certify a document. I would really appreciate if you can tell me if Post Office Certification would be approved by HMRC. Thank you very much,Kind Regards

Hi ali oztoygar,
The certified copy must be signed as a true copy and the certified copy must be signed as a true copy and stamped with a date by a government department, legal organisation or a medical body for example
in the UK:
Solicitors office
Doctor's surgery
The Post Office
outside the UK
Mayor's office
British Consulate.
Thank you. 

Ok, thanks. Kind Regards