Only these people can apply for someone else's birth certificate:
- a child's parent
- a person's child
- a child's legal guardian - evidence is needed for non-parent guardians
- the person's current spouse - evidence is needed if surnames are different
- an executor of their estate, administrator or trustee - evidence of authority is needed
- someone with written authority or power of attorney - evidence of authority is needed.
When applying for someone else's certificate you'll need to show proof of your connection to the person and give a reason for applying - e.g. a parent applying for their child's certificate, executor settling a deceased estate.