I have a single tax rate of 10% set up for CartThrob (including shipping which is a flat rate up to $400 then free after that) but the value being output in the cart is incorrect, it's coming out at about 10.6%.
I thought as a stop-gap measure, I could reduce the tax rate a bit so that when CT incorrectly adds a bit more, it would come out at 10%, but no matter what rate I enter, it always comes out wrong and I can never get it to equal 10%.
I've tried using both tax by location – percentage and with standalone tax database, but the results are the same for both.