By default Woocommerce allows you to define TO email recipients for New Order, Cancelled Order and Failed Order.
But if you are a manager or a business owner, you may be interested being notified when an order is successfully completed. By default Woo send this email to Customer only but it can be achieved by adding BCC email to Order completed email.
Thanks to Woocommerce super flexibility, it allows us to achieve this in a different way, using filter.
Here is the code snippet which goes into your child theme’s functions.php
Note: Change “email@example.com” email ID to suite your requirement.