First British Passport Document Requirements

Hi,

I’ve finally got to the point of applying for a passport, but the document requirements are confusing me.
They’re asking for “the passport used to enter the UK” which I do not have anymore and even if I do, I have no idea where it could be as I came here 13 years ago when I was 12 years old. I haven’t seen that passport in years, don’t even know what it looked like.
Can I just send in my current passport? I have no other passports with me so I don’t really know what else to do?

Also, off topic question but how likely is it to be asked to come in for a passport interview? That’s making me quite anxious so I want to know what to expect.

Thanks!

Send your current passport and naturalization certificate.

No need to be anxious about the interview you may not even be called for one. It is for confirmation of your identity not to review your application. I have had mine, loads of random questions, passport received a couple of days later.