Having trouble with your Twitter SMS account? Does Twitter not recognize you when you try to add your phone via text message? Don’t panic. You are likely running into a problem that can easily be fixed using these simple troubleshooting tips:
Start over. Text the word STOP to your Twitter code. This will cancel the phone activation process and you can start over. Text the word START to once again start adding your mobile phone to your account.
Check your username and password on the web. Go to Twitter.com on a computer and sign in to your Twitter profile. This will double-check that your username and password are correct. If you find your password isn't what you thought it was, request a new password here and we'll email you a reset link. (Since you're accessing Twitter via the web, try web-based phone activation.)
Avoid signatures and use of "Re:". Many phones will append a signature or "Re:" to text messages. If your phone is doing this, Twitter will not be able to recognize the username and password you've sent. Try again, and make sure your messages contain ONLY the characters in your username or password.
Watch for characters and capitalization. Do not include quotes, the @ symbol, or any other unnecessary punctuation in your text messages. Also, make sure your phone does not automatically capitalize the first letter of your password as passwords are case sensitive!