We have implemented a few different payment processor integrations and we have found there are separate APIs for a refund vs. void. I see the Square refund APIs but are there any APIs to do a void? Or is everything just a refund? Thanks.
If a payment is in an AUTHORIZED state you can call CancelPayment to void it. Otherwise every COMPLETED payment will need to be refunded. 
Perfect, I see that API now. Thanks for the quick response.