How to enable all charge accounts in a tax condition set

Hi Guys,

We're in the process of creating a new Tax Condition Set where the determining factor class = Accounting and the Determining Factor Name = Line Account. What we want to do is enable this for ALL charge accounts in the system.

We presume that you would set the 'Operator' to Range and add the first and last accounting codes in. However, how would you know which ones these are?

Also, during testing, we set the operator to 'Equal to' and supplied a charge account. This worked, but during testing we noticed that the tax calculated for other charge accounts which were different to the one specified in the test tax condition set. Can somebody explain this?