Birth certificate number

Have you picked the right thing because when I did my daughters I didn’t need to put in a number. It’s if they have a birth certificate from another country I believe

It’s the number at the bottom left corner

Applying for a child passport, you need to send their birth certificate regardless of if you apply online or via post.

Just applied and received our LO passport. We didnt need any numbers or info of the birth certificate. We just had to send his birth certificate to the home office. They send it back with the passport. Came back in one week using standard service

Bottom left :)