Incorrect DOB For Goverment Gateway

Hello, HMRC have advised me there is a discrepancy with my DOB when trying to log into Goverment Gatway and I need to send ID to amend. My questions are 1. Will my ID be sent back to me? Do I need to send by registered post with a return registered return envelop? 2. I read you accept out of date ID's - would my expired Irish passport suffice? 3. What is the correct address to send to, and do you sign to accept the mail? Thanks

Hi smarven,
To correct an incorrect DOB you do not send in an original ID document, you have to send in a Certified Copy of a Document confirming your DOB.
We accept main evidence of birth from a European Union (EU) or European Economic Area (EEA) country, which are certified copies of a
•    birth certificate
•    passport
•    driving licence
•    ID card - all parts of the ID card must be copied
If the main evidence of birth is not available, we will need two pieces of evidence that are certified copies.
These can be a
•    non EU or non EEA passport
•    certificate of naturalisation
•    home office travel document
•    certificate of baptism
•    certificate of service in Her Majesty's Forces
•    certificate of service in the Merchant Navy
•    marriage certificate
•    certificate of a civil partnership
•    adoption certificate
•    life assurance policy
•    medical card
•    copy of a statement of Royal Mail Pension Plan
•    excerpt of non EU or non EEA birth certificate
•    death certificate
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
•    Doctors surgery
•    Chartered accountants
Outside the UK
•    Mayor's office
•    British consulate
Neither of these lists is exhaustive and documents signed by other organisations may be taken into consideration.
The address you need to send the document too is:
PT Operations North East England
HMRC
BX9 1AN
You also need to write a cover letter with the following information:
•    Your National Insurance Number
•    Your full name including middle and any previous name
•    Your current address and any previous addresses, with the minimum as house or building number/name, the street name and the postcode
•    Your date of birth
•    Your signature
Thank you.