kyuk

While attempting to fill in the Self assessment form I found out that the date of birth on file is incorrect and that I am on or over state pension age. I wonder if someone is now cashing in on 'my' state pension? I was born abroad and therefor won't be able to get hold of a birth certificate fast. Would sending in my passport suffice to change my date of birth? The date on it is, after all, based on the original birth certificate I imagine. Or alternatively, would HMRC be able to sync my date of birth with the details of my National Insurance or with DVLA? Kind regards KYUK