Locking your debit card will prevent transactions until you unlock it. Keep in mind that this won’t prevent automatic bill payments or other scheduled transfers from occurring.
- Sign in to your account—online or on the Capital One Mobile app. (Text “MOBILE” to 80101 for a link to download).
- Select the account linked to your debit card
On the web: Choose “Account Services and Settings.” 
• Under “Account Management,” choose “Lock Your Card” and follow the steps.
On the app: Scroll down to “Debit Card Help” and select “Lock Card.” 
Lock or unlock your card now. Sign in to your account.
