It is possible to add a custom / own created PDF document to WooCommerce order emails. In plugin settings > general you will see an option to add up to 3 additional documents, that you can set.
![add additional PDFs to WooCommerce order emails](https://www.welaunch.io/en/wp-content/uploads/sites/8/2020/07/add-additional-PDFs-to-woocommerce-order-emails-1024x339.webp)
It will send mail with that pdfs attached plus the invoice.