Activate a Capital One debit card by signing into your online account through either the website or the mobile app and locating the Activate Card link within the Checking Account section. Click on the link, enter the last four digits of the card, and click Activate, as of 2015.
After you sign up for a Capital One 360 checking account, you have the ability to request a free debit card to be sent to you through the mail. However, it is not necessary to activate the card before using the online features of the account. Once the card arrives, you need to log into your account and enter the last four digits of the card on the activation page. If you don't have an account, you need to follow the online options to create one and associate it with your checking account.
The Capital One 360 checking account functions in the same manner as a traditional checking account, with the major difference being that there are no physical branches or branded ATMs for the bank. All account management takes place through either CapitalOne360.com or the appropriate mobile banking app. After activating the debit card, you may use it at any physical retailer that accepts cards with the matching credit logo or through many online stores.