Usually when you receive a new debit card in the mail, it has a sticker across it instructing you to activate the card before you use it. But it's possible you removed the sticker and stuck the card in your wallet without thinking, and now you can't remember if you activated it or not. Most banks offer multiple options for you to double-check your card's status and avoid a potentially embarrassing situation in which a cashier refuses your card.
Call Customer Service
All banks have a local or toll-free number for customer service, usually located on the back of your debit card. You can call that number to find out whether your card has been activated. If you prefer a more personal encounter, you can take your card into your local branch and a teller may be able to assist you.
Log in to Your Account Online
If you use your bank's online or mobile banking services, some allow you to activate your debit card simply by logging in online. If your bank does this automatically, you may have activated your card without even realizing it. If the activation isn't automatic, you can still use customer service resources at your bank's website to confirm if your card has been activated.
Use the ATM
Many banks activate your debit card automatically if you use an ATM to make a deposit or a withdrawal. Some banks only activate your debit card if you use their ATMs, however. At these banks, if you attempt to use another bank's ATM with a card you hadn't activated yet, the card won't work. However, a few banks will activate your card if you use it at any ATM.
Make a Debit Purchase
Some banks activate your card automatically the first time you make any debit purchase where you're required to use your four-digit PIN. This option would not apply if you ran your debit card as a credit card, or if you used it online.