To make a Capital One payment online, you must register your account number at CapitalOne.com. You can click on the "Pay Bill" tab on the homepage or the "Make a Payment" link under the "Payments" tab at the top of the main screen after you log into your account.
Capital One only accepts checks as a form of payment online for any of their financial services, as of 2015. Customers can set up automatic payments in the "Payment" section. You can also make a payment via the mobile application on your mobile device. The mobile application has many of the same features as the website, including chat support.