How do I activate a card for an authorized user? October 11, 2021 16:07 Updated All cards for authorized users can be activated by calling us at 855-301-4631. Then, they’ll be all set! Related articles Can I add authorized users to my credit card account? How do I log in and manage my credit card account? How do I activate my card? Will I be charged any fees while using this card? How do I start a loan application?