While living abroad as an expat, staying in touch with friends, family, business contacts, and associates—both in your home country and your new one—is essential. However, those international communication costs can pile up quickly.
After exploring multiple solutions, the most cost-effective and reliable option I've found is Voice over Internet Protocol (VoIP) using Callcentric. I've been a loyal customer for over 12 years, and I can confidently say their service is rock solid, with excellent reliability and availability.
This guide is tailored for Panama, but Callcentric provides telephony service in over 50 countries, so these steps should be adaptable no matter where you're living.
Why Use VoIP?
Let’s simplify things. When you use a regular mobile phone plan, you’re paying your carrier for all the towers, infrastructure, and connectivity—often at a premium.
With VoIP, you can make and receive calls using your internet connection, not your cellular network. That means:
Lower costs
Global access
Richer feature sets
No roaming fees
Here’s a high-level comparison:
📱 Cellular Network: Uses mobile towers to send/receive SMS and voice calls.
🌐 VoIP (e.g., Callcentric): Uses the internet to make/receive voice calls via an app or IP phone.
You can even continue to use your current cell phone.
Projected Costs:
How It Works (Diagram)
In this diagram:
SMS and cellular calls flow through the mobile network.
VoIP calls use a SIP client (like Linphone) configured on your device.
Callcentric routes the calls over the internet, bypassing local telecom rates entirely.
Getting Started: Step-by-Step
1. Create a Callcentric Account
Sign up at callcentric.com
Choose a phone number (DID) from the U.S. or another supported country
- I chose both U.S and Panama
Subscribe to inbound and outbound calling options (either per-minute or monthly packages)
Don’t forget to enable 911 service (mandatory in most countries)
2. Configure Your SIP Credentials
After setup, you'll receive:
A SIP username (e.g.,
17775551232)The SIP domain:
sip.callcentric.netA SIP password (create one that's long and secure!)
Example of a SIP client configuration screen:
Fill in your credentials just like this, using your own username/password. Make sure to use UDP transport unless otherwise specified.
3. Install a SIP App
I recommend Linphone, a free and open-source SIP client available for iOS and Android.
Once logged in, you're ready to make and receive calls over Wi-Fi or mobile data, with zero reliance on your mobile voice minutes.
Here’s an example of an incoming VoIP call :
4. Test & Optimize
Place some outbound test calls
Have someone call your Callcentric DID number
Ensure voicemail is working (set it to answer after 35 seconds)
Configure Caller ID (CNAM) for better identification
You can get fancy with call treatments and routing:
Use Case: Panama & USA Numbers
With Callcentric and Linphone installed:
I can receive calls to my US number and Panama number on my phones in Panama (or anywhere I have a cell signal)
I can also make calls using my Panama number, and it will show correctly to recipients
No international fees, no roaming charges, just a flat-rate VoIP subscription
Final Thoughts
Whether you're an expat, digital nomad, or simply looking to cut telecom costs, setting up VoIP with Callcentric is a game-changer. With minimal setup and low recurring fees, you can stay connected globally, seamlessly.
If you've ever struggled with high international rates or missed calls while abroad, this setup will feel like a breath of fresh air.
Try it, test it, and see how easy it is to make your phone smarter and more economical—no matter where you live.
