I have a Buy X Get Y coupon that I've set up with an automatic discount to automatically add a free product to the cart if the shopper is from the state of Colorado. This works as expected if the shopper does not have separate billing and shipping addresses. However, if the shopper does have separate billing and shipping addresses, we want this coupon to execute if the *shipping* address is in Colorado. Currently the coupon only triggers based on billing address.
Is there a way to get the coupon to look at the shipping address if it differs from the billing address? If not, can someone point me to the best place in the PHP code where I could implement this myself?
Thanks.