title: How to share a single Twilio number between multiple clients?
body: <p>I'm creating a twilio service with three actors:</p>
  
  <ul>
  <li>The <strong>customer</strong>, a person who calls a company</li>
  <li>The <strong>company</strong>, a company who forwards calls to the service-provider</li>
  <li>The <strong>service-provider</strong> (that's us), an entity that services the customer on behalf of the company</li>
  </ul>
  
  <p>Herein lies the catch: <strong>The service provider needs to be able to identify the company associated with the customer</strong> but it may only use a single phone number. We cannot use multiple phone numbers for cost reasons (the margins are <strong>that</strong> low). We cannot use the caller id because a single customer may be associated with multiple companies.</p>
  
  <p>I am familiar with Twilio's <a href="https://www.twilio.com/docs/api/twiml/twilio_request" rel="nofollow">ForwardedFrom</a> field but as mentioned <a href="http://forum.twilio.com/twilio/topics/i_am_getting_inaccurate_forwardedfrom_data" rel="nofollow">here</a> it isn't always reliable. In fact, forwarding from my cell-phone carrier results in a null <code>ForwardedFrom</code> field.</p>
  
  <p><strong>How can we (reliably) identify the company who redirected a customer to us without using multiple phone numbers?</strong></p>