Non-Stackable Error Message Needed
When coupons are set to be non-stackable and someone tries to enter more than one, I think a error message should pop up stating that only one coupon is allowed per order. Right now people keep trying and then complain that the system doesn't work.
Cher Nicastro commented
I just had an ugly customer experience because of this exact problem. I can't believe that this hasn't been fixed yet!