Coming from Invoice Simple?

1. Open Invoice Simple and go to Settings.
2. Under the Invoice heading, tap Export Invoice Summary.
3. Pick a date range that covers all your invoices (start it before your very first invoice).
4. For the file format, choose CSV. (XLSX works too. Don't pick PDF.)
5. Tap Export. The file saves to your phone or computer.
6. Come back here and drop that file in the box above, or tap Choose your file and pick it.

On a phone, the saved file is usually in your Files or Downloads. Steps from Invoice Simple's help page. What comes over: clients, invoice numbers, dates, tax, totals, payments, and PO #. Invoice Simple's export doesn't include line items, so each old invoice gets one summary line.