No you don't. To be a tankie you have to have driven a tank in civvy street. If you've driven a tractor or a bulldozer then you only need to convert to driving a challenger, though if you can prove you drove a bulldozer with a piece of drainpipe sticking out to the front to mimic a 120mm gun then you will be okay.
Tom don't listen to the nasty people.
You are correct in what you say. At the Tank Training School in Bradford is where it all happens.
Contact you nearest Army Careers Office and ask for the Tank Crew Loader Training CD so you will have a head start on your fellow recruits, this will enable you to get promoted in the first two weeks of your training and if you have sucessfully learned how to drive the tank/bulldozer you will be put in command of the tank which means you have a license to fire the gun in any town.