# Citi Card Activation Guide

- [Citi Card Activation Guide: Activate Your New Card Fast](https://citicardactivationguide.mintlify.app/index.md): A simple guide to activating your new Citi credit card online, by phone, or in the Citi Mobile App, plus what to do after activation and how to fix problems.
- [What You Need Before Activating Your Citi Credit Card](https://citicardactivationguide.mintlify.app/quickstart.md): Check what information you need to activate your Citi credit card, such as your card security code and the last 4 digits of your SSN, before you begin.
- [How to Activate Your Citi Credit Card Online at Citi.com](https://citicardactivationguide.mintlify.app/activate/online.md): Step-by-step instructions to activate your new Citi credit card online at Citi.com/activate, including what details to enter and how to confirm it worked.
- [How to Activate Your Citi Credit Card by Phone](https://citicardactivationguide.mintlify.app/activate/by-phone.md): Activate your Citi credit card by phone by calling the number on the back of your card or activation sticker and entering the details the system asks for.
- [Activate Your Citi Credit Card in the Citi Mobile App](https://citicardactivationguide.mintlify.app/activate/mobile-app.md): Use the Citi Mobile App on iPhone or Android to activate your new Citi credit card by signing in and following the in-app activation prompts.
- [What to Do After You Activate Your Citi Credit Card](https://citicardactivationguide.mintlify.app/help/after-activation.md): Learn when you can start using your Citi card after activation, how to check if a card is already active, and the first steps to take with your new card.
- [Can't Activate Your Citi Credit Card? Try These Fixes](https://citicardactivationguide.mintlify.app/help/troubleshooting.md): Fix common Citi card activation problems: check the details you entered, try another activation method, or contact Citi customer service for help.
- [Citi Card Activation FAQ: Answers to Common Questions](https://citicardactivationguide.mintlify.app/help/faq.md): Answers to common Citi card activation questions, like why activation is required, what happens if you don't activate, and how soon you can use your card.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.