Smart & Connected Life Working From Home How to Set up Two Factor Authentication on iPhone Plus, how to turn off two factor authentication By Sam Costello Writer Sam Costello has been writing about tech since 2000. His writing has appeared in publications such as CNN.com, PC World, InfoWord, and many others. our editorial process Facebook Twitter Sam Costello Updated March 17, 2020 Working From Home The Ultimate Guide to Shopping Online The Ultimate Guide to Online Learning at Home The Ultimate Guide to Skype Tweet Share Email You can't be too careful with security on your iPhone, and one of the best ways to secure your phone is with two factor authentication (2FA). With two factor authentication for iPhone, it's much harder for hackers to break into your phone and access your data. This article was written using iOS 13, but the basic concepts apply to all recent versions of the iOS. The exact steps or menu names may be slightly different, but should be fairly similar. Janis Engel / EyeEm / Getty Images What Is Two Factor Authentication and Why Should You Use It? Two factor futhentication (2FA) is a security system that requires that you have two pieces of information to access an account. The first piece of information, or factor, is a username and password combination. The second factor is usually a randomly generated numerical code. That's how Apple's 2FA system works. It uses your Apple ID username and password as the first factor and then randomly generates a code when you try to sign into your account. Because each code can only be used once, the system is harder to break. Two Factor Authentication is built into the iOS, macOS, iPadOS, tvOS, and Apple websites. Two Factor Authentication is not the same thing as Two Step Verification, which is an older––but less secure––option Apple offers. Two Step Verification only works on iOS 8 and earlier, and macOS X 10.11 As long as you're running new software than that, you can only use Two Factor Authentication. How to Set Up Two Factor Authentication on iPhone Turning on two factor authentication on the iPhone will secure both your Apple ID and the features of your iPhone that use your Apple ID. Here's how to set it up: Tap Settings. Tap your name at the top of the screen. Tap Password & Security. Tap Turn On Two-Factor Authentication. Tap Continue. If you're asked to answer any of your Apple ID security questions, do so. As part of the setup process, you will receive a verification code by text message or phone call. Entering the phone number on which you want to get the code. Choose to get the code by Text Message or Phone Call. Tap Next. When you get the code, enter it. Two Factor Authentication is now turned on your for your Apple ID and iPhone. Your Apple ID isn't the only sort of account you can secure using Two Factor Authentication. Use the feature to enhance the security of all kinds of accounts, including Facebook, Gmail, Fortnite, and Yahoo Mail. How to Add Trusted Devices on iPhone As an additional layer of security, you can only use Two Factor Authentication to sign into your Apple ID on a trusted device. This means that even if a hacker could get your Apple ID username and password and the one-time-use code, they'd also need physical access to one of your devices to get into your account. Pretty secure! To add a trusted device to your account, follow these steps: Start with a device that you haven't yet used with Two Factor Authentication. This should be a device you own, not a friend or family member's device. You'll also need your iPhone nearby. Sign into your Apple ID. On your iPhone, tap Allow in the pop-up window that lets you know someone is signing into your Apple ID. On the new device, sign in using the six-digit code sent to your iPhone. Now, both your iPhone and the second device are trusted and can sign into your Apple ID without performing Two Factor Authentication again. Repeat this process for as many of your devices as you'd like. How to Remove Trusted Devices on iPhone If you're getting rid of a device that you trusted in the past, you need to remove it from your list of trusted devices. If you don't, the next owner of the device might be able to access your account. To remove a device from your Trusted Device list: On your trusted iPhone, tap Settings. Tap your name. Scroll down to your list of devices. Tap the device you want to remove. Tap Remove from Account. In the pop-up window, tap Remove. How to Turn Off Two Factor Authentication on iPhone Interested in turning off 2FA? You can't. Once you set up two factor authentication on iPhone (or any other Apple device), you can't turn it off. That may sound strange, but it's actually another security measure. Turning off two factor authentication would make your devices and your Apple ID less secure and Apple doesn't want to allow that. If you have detailed questions about how 2FA works or what to do in certain complicated scenarios, you can learn more from Apple's support for for two factor authentication.