Frequently asked questions (FAQ) about voice services

Find answers to your questions from our FAQ about how to get started with voice services with CallnFax and more.

CallnFax LOVES Flat-Rate inbound service. Imagine a DID with 100 incoming channels and No Per Minute Charges!

Most of our local, national, and mobile DID’s offer a fully Flat-Rate option, no matter how many calls you receive. We don’t burden you with “Fair Use Policies” or throttle service once you are busy. For CallnFax, Flat-Rate means Flat-Rate!

CallnFax bills at 6-second intervals, and our A-Z Termination rates are highly competitive, full CLI, and mostly carrier-direct connections.

CallnFax is proud to use PayPal™ as our payment carrier. We accept all major credit cards. Your purchases are safe and secure, with PayPal™ and CallnFax.

Starting service with CallnFax is easy. You will need a valid email address and a text-enabled device to register with CallnFax. We secure all accounts with Two-Factor Authentication, for your protection. 

CallnFax works great for personal use! Here in Canada, for example, many people have family in other countries, and CallnFax makes staying in tough easier. Keep a phone number from your home country. In many cases, you can even keep your old telephone number!

CallnFax offers Local Number Portability, so you can keep your old telephone number, regardless of where you are now living. 

For example, you moved to New York City, from Berlin. With CallnFax, you can keep your old mobile number, home phone number, or even a business number!

Finding your new Inbound Phone Number, is simple and intuitive. 

Our Location Finder Tool makes searching our wide selection of inventory, easy:

Inbound Number Finder

It is easy to find and search our Outbound rates. With over 30,000 rate centers, searching and finding your exact rate is simple with our Rate Finder:

A-Z Termination Rate Finder - Inbound Service FAQ

Configuring your SIP Trunk with CallnFax is simple. We use a modified Asterisk system for standardization, and ease of registration.

There are many different SIP Trunk platforms, and the following is a General Rule in configuration.

Your system may have different rules and configurations.

If you need support, please reach out to us, as we are happy to help!


General Trunk details:

username=[SIP username]





host=(this will be sent by email)








Registration string:



Contact Info