To activate your Citibank card without the physical card, call our toll-free helpline at 1-888-388-4751 or log in to your Citibank online account or mobile app. Go to the “Activate Card” section and follow the instructions to enter your card details and any necessary personal information. If you face any issues or require additional help, contact us immediately at 1-888-388-4751 for smooth and secure card activation.