Macaw Invoice Processing - Tired of manually opening invoices and typing the amounts in Excel for your tax returns ? Macaw to the rescue! Macaw is an easy-to-use tool that allows you to open multiple invoices at once, and even better.. it will in most cases detect the total amount due of each invoice! You just have to confirm that the amount is correct with a simple click of your mouse button. The output will be an Excel file that you can use straight away.