The Billing History in the profile settings shows all payments made to Readymag. Here you can download a receipt for each payment in PDF, just hover over the link in the Invoice field and click Get a receipt. Note, Readymag does not provide invoices, but if you need additional contact or tax information added to your receipts (business address, VAT number, etc.), enter it in the blank text area and it will appear on all of your receipts.