My Boss Is Asking My To Edit Invoices For A Spiff Claim

The company I work for buys equipment from manufacturers and sells them to distributors. We have a strict zone policy of where we can sell them but sometime my boss will sell to other ditributors outside of the zone without the manufacturer knowing. The manufacturer is offering a SPIFF (a partial money return) for some equipments if we manage to sell them but they ask for a copy of the invoice to claim it. My boss has asked me to take those invoices that have been done to outside our permitted zone and edit the distributor details to another one inside our permited zone. How legal is this it feels sketchy but I dont wanna loose this job??? please help, I am in Mexico but my company and manufacturers are working from the US.