Help G325a issue

[iamfrvr22]

My spouse does not know his father's Date of Birth, he died when he was two, on his birth certificate he only has his mothers name, will it affect the process if we do not put the date of birth on the G325a

[hotelier73]

He should ask his relatives if they could help him. If not that could be explained on a cover sheet

[iamfrvr22]

We did all that, no one remembers really. I asked a lawyer and he said to write unknown, especially he is not named on his birth certificate.