What prior experience of tax did you have that inspired you to become a Tax adviser?

Hey,
To be honest I had no experience. I didn't even apply for tax in my original application but I think I'm pretty lucky that is where I ended up.
As for learning and working for clients without this, well that's what make it interesting. From the moment you start you are learning, whether this is basic tax layouts and rules or researching and evidencing obscure tax rules.
EY are also pretty good at realising people require an initial help and training so all tax grads are sent on an internal tax training course which gives you a base of skills and knowledge to build on.