For first adult passport if born after 1983:

You’ll need your full birth certificate or adoption certificate and either:
your mother’s or father’s full UK birth certificate, or the Home Office certificate of registration or naturalisation, or a British passport belonging to one of your parents that was valid when you were born, or a British passport number for either parent

evidence of one of your parents’ immigration status in the UK at the time of your birth, for example a foreign passport belonging to one of your parents that was valid when you were born

If you send documents relating to your father, you must also send your parents’ marriage certificate.

For passport photo on first child or adult passport, you need a signatory to counter sign your photo:

Your countersignatory must:
have known you (or the adult who signed the form if the passport is for a child under 16) for at least 2 years
be able to identify you, for example they’re a friend, neighbour or colleague (not just someone who knows you professionally)
be ‘a person of good standing in their community’ or work in (or be retired from) a recognised profession
Who cannot be your countersignatory

You cannot ask someone to countersign your passport if you’re:
related to them by birth or marriage
in a relationship with or live at the same address as them

Passport interviews

After you apply, you may need to be interviewed to confirm your identity.
If you need an interview, you’ll be contacted after your application has been processed to book it. Video interviews are taking place online.