@Jackie Yang I don't think there is really a great way to handle this. Probably inventory adjustments after the fact. I'd recommend focusing on the shipping process so items can be scanned at time of shipping. If the order is for ABC and someone picked XYZ, it should get stopped before the fulfillment goes out. Trying to fix it on the return side because more labor intensive. I could think of some custom scripting where you'd define the "correct" item in some custom field and on save of the return, the adjustments get done automatically...but that's still a band-aid. I'd try to stop the bleeding upstream. Good luck!