One of the most misunderstood features of Phaxio is what happens when you use test API credentials. If you’ve been using test credentials and your faxes aren’t printing out at a fax machine, don’t panic. That’s what’s _supposed_ to happen.

If you are using test API credentials Phaxio will simulate sending or receiving a fax through the Phaxio system. This means that we won’t make phone calls and nothing will print at any fax machine. Phaxio will give you a fax ID as well and everything else that you would expect to happen will occur except for there will be no live telephone calls.

You can use test credentials to test your integration with Phaxio. Here are some cases where this is useful:

• Ensuring your documents are rendering properly
• Ensuring your documents are accessible by Phaxio (if using a url)
• Verifying that your batching settings perform as you’d expect
• Testing your callback URL

Make sure that when you go to production that you swap the test creds for live ones or your faxes won’t actually be delivered.

Happy faxing!