1. X (Twitter)delivers the code
  2. Your +1 numberreceives the text or call
  3. TripoSIM appshows it on your phone
How X (Twitter) delivers codes:Text messageAuthentication appSecurity key

X (formerly Twitter) asks for a phone number in some sign-up and security steps, and a confirmed number helps you recover the account. A US number in the TripoSIM app gets X’s text codes over Wi-Fi or mobile data, wherever you live. Every X step below is from the X Help Center.

How does X deliver its codes?

X sends a confirmation code by text message when you add or confirm a phone number. The TripoSIM US number receives it in the TripoSIM app. TripoSIM tested X on October 3, 2026.

For two-factor authentication, X offers three methods: text message, an authentication app, or a security key. Text message two-factor is only for X Premium subscribers, and X says its availability may vary by country and carrier.

How do you add your US number and turn on two-factor?

On the X app for iPhone (Android and desktop are similar):

  1. From the main menu, tap Settings and privacy, then Security and account access, then Security.
  2. Tap Two-factor authentication.
  3. Pick a method. With Text message (Premium only), tap Get Started, enter your password and confirm your email if X asks. If no phone is on the account yet, X asks for one: enter your US number with +1.
  4. Enter the confirmation code from the TripoSIM app.
  5. Save the backup code X shows, then tap Got it.

Not on Premium? Choose Authentication app and scan the QR code with any time-based (TOTP) app, or choose Security key. X says a security key can be your only method.

What if you lose access?

Use the backup code X gave you at setup. It is meant for when you lose your phone or change your phone number.

Keep the number too. If your TripoSIM plan ends, the number is kept 30 days on the yearly plan or 90 days on the monthly plan, then released. See number recycling and account security.

What if the code does not arrive?

  1. Check the country code (+1) and the 10 digits.
  2. Check the TripoSIM app is online with notifications allowed.
  3. Text 2FA greyed out or removed? That is X’s Premium rule, not the number. Switch to an authentication app.
  4. Still nothing: contact X support. For the number itself, contact TripoSIM support.

The number receives texts but cannot send them, so it cannot reply to X by text. For other apps, see which apps send codes to the number or the app check tool.