How can I reactivate the Citi Mobile for Cards Application after deactivation?
On the Tools & Services page in Account Online, choose More Details under Citi Mobile for Cards. Once you’re on the Manage Citi Mobile for Cards Application page, just select the device that was already deactivated and then select Activate Device. You will receive an Activation Code that you will enter into your mobile device. After successfully entering the code, you will be prompted to create and confirm a new PIN.