Do we need to pay a deposit on the school fees?

Nope, 3x.
Well EU students pay around 6k++
International students pay 9k++
And thats pretty steep for a foundation year.
But that's no big deal at all. The ****ty part for me is accomm. My accomm fees are more than tuition fees.

Hiya, I'm pretty sure EU students pay the same as UK 'home' students which is £3145 this year.
http://www.kcl.ac.uk/ug/funding/home.html
I'm from the UK and my EU friends paid the same amount as me last year. If you are in London right now I'm sure you can go to KCL and pick up all the forms you need if they haven't come in the post. If you are in halls then international orientation starts from the 6th Sept. Hope this helps