Hey @samwallermuseum, welcome aboard Square's Seller Community!
At the moment, it's not possible to input previous sales from a different payment processor into Square's reporting. Square can only generate a report from sales taken using Square's Hardware or Software systems.
I think it is a great idea that would be useful for tracking and reporting purposes, though. I'll make sure to pass that feedback over to our team to take into consideration.
Let me know if there's anything else I can help out with! 😊
