If you've got a working phone or computer, you can use either to activate a Discover Card. If you received multiple cards, you will need to activate each one separately.
Discover's activation page is at (https://www.discovercard.com/cardmembersvcs/acctxfer/app/Home?vcmpgn=discover_activate). Logging in is the simplified version, only requiring you to enter your Discover user ID, password and 3-digit sequence ID. To activate without logging in, enter the primary cardholder's date of birth, social security number, the 16-digit card number, its 3-digit sequence ID number.
Call 866-847-2350, or call the regular customer service number 800-DISCOVER and request to activate a card. The cardholder or an authorized user can do the activation as long as the caller has the cardholder's personal identifiable information. You must have the new card in hand to answer any questions.
Discover Gift Card
You can also activate a Discover gift card online. Go to the Discover Gift Card activation page and enter your card number and cardholder ID. Your cardholder ID is on the back of the card where you sign your name. You must contact customer service at 866-522-7026 if you need help or need to replace a lost or expired card.
Cash Back Bonus
Discover offers up to 5 percent cash back in certain categories, and 1 percent cash back on everything else. You have to activate the 5 percent cashback bonus category. The bonus category changes each quarter and must be activated each time. Check the Discover Cashback Calendar to see which bonus categories are planned for the year. You can activate the current bonus category from the same page.