Remember, the audit is not going to be tomorrow, when things will be fresh in your mind. It will be three years away. That's three vacations away. Three Christmas's away. Three Fourths of July away.
You have to document things so that you'll be able to figure it out in three years. A good way to do so is to prepare your notes as if you won't be the person reading them, and trying to explain things to the auditor. And you probably won't.
There's a good chance you're going to be doing something different in three years (hopefully you got promoted out of having responsibility for sales and use taxes). And even if the
So document like it won't be you.
Sales Tax Guy