Use SIP2SIP to receive unlimited incoming calls on your FlyNumber

Here’s a simple tutorial on how you can use the Zoiper app and sip2sip to receive unlimited incoming calls on your FlyNumber (ie. Virtual phone number)

This does not require the use of our cloud PBX system.

Quick mention: If you haven’t noticed we’ve updated our PBX-phone system. It’s a powerful system and currently priced at $13 a month (We suggest you check it out and lock in price as it will be going up soon)

First you’ll need an account from sip2sip, it’s free and simple to sign up. I’ve used them for years and never had an issue. (Check your spam/junk folder for their emails).

You can set multiple numbers to the same SIP2SIP account.

For example, you can have a number in London and a phone number in Sydney ring to the same Zoiper account

Take your account username and password ( the ones from and enter them into a SIP client , a free one for iOS and Android is Zoiper ( we really like “Groundwire” , one-time paid app but worth it)

Choose “Yes” to “Do you have a username and password”, and then “manual configuration”

You’ll only need the user, password and domain (which is

Add SIP account options with fields for domain username and password
Zoiper add SIP account screen


Under “Network settings” for the account you just created, change Transports to TCP and disable STUN as you see below

Network setting options screen for transports and STUN
Network settings screen from the Zoiper app

Final Step

You’ll need to set the forwarding on the FlyNumber side to a VOIP provider

On FlyNumber ( Under “My FlyNumbers“)

Change the forwarding to “VoIP” , screenshot below

Protocol is SIP

Host is

“details” is testingforfly (in our case)

Screenshot of the FlyNumber change forwarding panel
Change forwarding option on FlyNumber user panel

All set, calls from your local FlyNumber will now ring to your app.

There are a bunch of settings on sip2sip you can check out as well ( voicemail etc.)

By Nader Jaber

Helping people communicate while trying to improve as a communicator myself.