To lock your Wells Fargo Card - open the Wells Fargo website. When the main page loaded - find login form. Type your username, password and click Sign On. When the first screen is loaded - find the checking account that is linked to your debit card. When details of the Wells Fargo Checking account loaded - find “Turn Card On or Off”. On the card controls page, find the “Card on or off”. If it is Green - then the Card is unlocked. But if the switcher is Gray - it means your Wells Fargo debit card is locked. You can do the same for your other cards. For example, I can turn off my Wells Fargo Credit Card.