You have the ability to set your Tax Rates based on your Client Classifications.
First you will need to create your Client Classifications to use. Go to Settings > Client Classification menu. Add the Client Classifications that you would like to use with your Tax Rates.
Then go to Settings > Payments, and select the Client Classification Type under the Tax Setup section. Add your Tax Rates. Note: The Tax Rate must have the same name as the Client Classification.
Once the new Tax Rates are set up, go to the Client and set the Client Classification to the appropriate classification that matches the tax rate.
You have completed your Tax Rate setup. Going forward, your client will be taxed based on the Client Classification Tax Rate that you have assigned them.