confusion about citizen by birth or naturalisation

[mateen123]

Hi

My son was born in Dec 2013 when both me and my wife were on Tier-1 visa in UK. Then in Jan 2014 I got ILR and applied British Passport for him. My company lawyers did the processing and they did all the documentation. Now I'm trying to apply for India visa for him and have the following questions:

1) Is my son a British citizen by birth or thru Naturalization.
He had to go thru a Registration process, and has a registration as British Citizen certificate. Not sure if this is same as Naturalisation.

2) What is his citizenship ID.
Is this same as his passport number.

Although these questions are related to India Visa, but I think they are specific to UK passport status. So I am thinking this is the right place to post.

Looking forward for replies. Thanks,
Mateen

[Amber]

1. British through registration.

2. Number on the registration certificate.