To update your billing information with Petnetdirect.com, you typically need to log in to your account on their website. Once logged in, go to the account or profile settings section where you should find an option for managing billing information. There, you can add a new credit card, update your address, or make other necessary changes. If you do not have an account or are experiencing difficulty accessing your account, you may need to follow the prompts provided on the site for assistance. For further guidance, users can look for help resources on the Petnetdirect.com homepage or check their FAQ section. It is always a good idea to ensure that your billing information is current to avoid any issues with future orders.