I can't add 2fa to my account because it keeps sending me sign in codes

Follow these steps to break out of the verification-code loop and get 2FA (MFA) set up more reliably:

1. Avoid triggering temporary blocks

• Do not repeatedly click Send code or switch methods rapidly; this can cause Microsoft to temporarily block sending codes due to unusual activity.
• If many attempts were already made, wait for some time (the block auto-clears) before trying again.

2. Make sure the verification channel actually works

• For SMS:
  • Ensure the phone is not blocking texts from unknown numbers.
  • Confirm the inbox is not full and the messaging app is working.
  • Use a mobile number, not VOIP; VOIP numbers cannot be used for verification codes.
• For email:
  • Check the correct mailbox (primary alias or added verification email).
  • Look in junk/spam for messages from @accountprotection.microsoft.com and mark them as trusted.

3. Verify or correct security info first

• Go to the Security info page for the Microsoft account and check that the phone number or email is entered correctly. Only the last two digits (phone) or first two characters (email) are shown during sign-in, so confirm they match.
• If the listed method is wrong or inaccessible, choose I don't have any of these (or equivalent) to replace the security info with a working phone/email.

4. Reduce reliance on SMS and use Authenticator Once a working verification method is in place and codes arrive normally, add a stronger method so future loops are less likely:

• Add Microsoft Authenticator as a sign-in/verification method.
• After Authenticator is set up, keep at least one backup method (another email or phone) so the account is not locked to a single factor.

5. If codes still do not arrive

• For a personal Microsoft account, use the sign-in helper tool if sign-in itself is failing.
• If still stuck, use the Contact Microsoft Support path described in the verification-code troubleshooting article to get technical help. Note that support agents cannot send codes or change account details but can help diagnose delivery issues.

These steps ensure a valid verification method is working first, then allow adding 2FA without being trapped in a send-code loop.

References:

• Troubleshoot Microsoft verification code issues
• Common problems with two-step verification for a work or school account