Conditionally apply a tax zone in commerce Many of the customers we'll be selling to are tax-exempt entities. We're located in OH, so for OH customers we're applying sales tax through the Tax Zone setup in Commerce. Is there a way to not apply the tax based on some conditional, even though their billing address is in OH?
OK So I figured this one out eventually. It's a very hacky fix. I added an adjuster that is basically an exact copy of the built-in Tax Adjuster (found at plugins/commerce/Commerce/Adjusters/Commerce_TaxAdjuster.php). The only difference is that I added a condition to check for my Tax Exempt field (and that we're in the OH tax zone), and then removed the tax amount instead of added it.

ie, I changed things like 

$allRemovedTax += $amount;
$item-&gt;tax += $amount;


to

$allRemovedTax -= $amount;
$item-&gt;tax -= $amount;


And then added the whole thing to a new custom plugin.

What this results in is tax being applied normally, and then the same tax being removed. 



If anybody comes across this and has a better solution, I'd love to hear it. But this works for now.