The United States-Mexico-Canada Agreement (USMCA) took the place of NAFTA on July 1st, 2020. Some shipments that cross the borders of these countries may require special import forms.
At this time, ShipStation does not print these forms or provide a way to electronically upload them. If you require a USMCA form for your international shipment, you will need to create it outside of ShipStation and include a physical copy of the form with the parcel.
For USMCA details and forms, go to the U.S. Customs and Border Protection USMCA page. For NAFTA details and forms, go to the U.S. Customs and Border Protection NAFTA page.