Can you sign up for the British army online?

Answer 1

Contact the British Army and ask them.

Answer:

It seems unlikely. There'd be interviews, tests and so forth (including a medical which even today is rather hard to do via the internet).

You don't just apply, get accepted and start: they like to decide if you're suitable or not and what your aptitudes are.

Answer 2

For one to sign up for the British Military the first step is to locate the local army directory. To do such a task one needs to log on to the army website, and click the tab joining the army. After which it will ask for ones postal code, and then it will give one the nearest address and phone number for said location.