You can generate an invoice for you purchase through your WP Charitable account area.

In the menu on the left, click on “Your Purchases”.

Next, find the purchase you would like to get an invoice for and click “View Invoice”.

Go to the Purchases tab and click on Generate Invoice for your purchase.

On the following page you can download your invoice or print it. If you need to change your billing details for the invoice, click on the Update button in the “Invoice to:” section.