In a nutshell
Two-factor authentication is a way to check once more, on top of your password, with something only you have. You can't log in unless you have both something you know (the password) and something you have (such as a smartphone).
How the methods differ
X's Help lists three methods of two-factor authentication: SMS (text message), an authentication app, and a security key (How to use two-factor authentication, as of October 2026).
| Method | How it works | Good for |
|---|---|---|
| SMS | Enter the number you receive | When you want an easy start |
| Authentication app | Enter the 6-digit number shown in the app | The recommendation in most cases |
| Security key | Plug in or tap a dedicated key | When you want stronger protection |
The number in an authentication app is generated every 30 seconds inside the app on your device and doesn't rely on receiving text messages. If you can choose, use an authentication app rather than SMS, so you are less affected by problems with phone numbers.
What to watch for with official accounts
If an official account is taken over, the damage can spread to customers through fake announcements and impersonating DMs. The more it is a company account, the more important it is to turn on two-factor authentication first.
Recovery codes (backup codes) are provided when you set it up. They are a spare key to use if you lose your smartphone, so don't keep them only on the person in charge's personal phone; store them in a place your company has decided on. Don't forget to hand them over when the person in charge changes. The overall approach to preventing takeovers is explained in How to protect an official account from takeover.
Set up two-factor authentication not only on your social media accounts but also on the logins of the tools connected to them. If a tool is taken over, posts can be made from there. How tools are connected is explained in OAuth, and the cap on login attempts in Rate limit.
In SNS TOWN
You can also set up two-factor authentication with an authentication app for your SNS TOWN login, and 10 recovery codes are issued. There is also a setting, per company or brand, that requires two-factor authentication from all members. The details are explained in Account protection.
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