title: Twilio - The From phone number xxx is not a valid, SMS-capable inbound phone
body: <p>I want to use Twilio for verifying phone number of users registering on my app.
  As a backend, I have Parse.</p>
  
  <p>I tried to send an SMS using the test credentials, so far I received a success message, but, I didn't received the SMS!
  I've tried to switch to the live credentials; however, I received the following:</p>
  
  <pre><code>{
      "code": 141,
      "error": {
          "status": 400,
          "message": "The From phone number +12025550162 is not a valid, SMS-capable inbound phone number or short code for your account.",
          "code": 21606,
          "moreInfo": "https://www.twilio.com/docs/errors/21606"
      }
  }
  </code></pre>
  
  <p>I've also tried to replace the "From" Phone number to an alphanumeric sender ID, but that didn't work too!</p>
  
  <p>What should I do in that case?</p>