Easy Digital Downloads has the ability to import payments in a CSV format.
Payment importing is done under Downloads → Tools → Import/Export.
On this page, you’ll find a box labelled Import Payment History.
Your CSV should be comma-separated, with fields enclosed by double-quotes. The order of the fields is not important.
Click Choose File and browse to your file. Then click Import CSV.
Once your file is uploaded you’ll see a list of Payment fields that need content, and a dropdown for each one, where you can map where the data is. Each dropdown will be populated with content from your CSV