You can activate your USAA card in the following ways – Online Method: Visit usaa.com/activate, enter login details, and provide your card details to activate the card. Phone Number: You can dial 800-411-4300 (for credit cards) or call 800-315-4906 (for debit cards) to activate USAA cards. ATM: After receiving your USAA debit card, you can visit the nearest ATM to activate your card. Use the card and follow the on-screen prompts to complete the process.