The NBN Telephone Line is an essential component of Australia‘s broadband infrastructure, enabling voice communication over the National Broadband Network (NBN). As the traditional copper-based telephone network is being phased out, it is crucial to understand which devices are compatible with NBN phone services.
In this guide, we will explore the types of devices that work with NBN telephone lines, potential compatibility issues, and how to ensure seamless connectivity in your home or business.

Table of Contents
Understanding NBN Telephone Line Compatibility
NBN telephone line compatibility depends on the type of NBN connection you have and how voice services are delivered. Unlike traditional landline phones that operate through copper wiring, NBN voice services use digital technology. Here’s how your telephone line may function:
Provides a dedicated voice service separate from the internet.
1. VoIP (Voice over Internet Protocol)
- This is the most common method for making calls over the NBN.
- Requires a modem/router with VoIP capability.
- The phone connects to the modem instead of a traditional wall socket.
- Suitable for connections like Fibre to the Node (FTTN), Fibre to the Curb (FTTC), and Hybrid Fibre Coaxial (HFC).
2. UNI-V Port on the NBN Connection Box
- Available only for Fibre to the Premises (FTTP) connections.
- Allows direct connection of a landline phone without needing a VoIP modem.
Compatible Devices for NBN Telephone Line
The following table outlines the common devices that work with NBN telephone line and their compatibility status.
Device Type | Compatibility with NBN Telephone Line |
---|---|
Standard Corded/Cordless Phones | ✅ Compatible with VoIP-enabled modem or UNI-V port |
Medical Alert Systems | ⚠️ May require reconfiguration or an alternative solution |
EFTPOS Machines | ⚠️ Some models may need an upgrade to IP-based systems |
Security Alarms | ⚠️ Many traditional alarms need an NBN-compatible upgrade |
Fax Machines | ⚠️ May require special settings or an alternative service |

Common Issues and How to Resolve Them
1. No Dial Tone on NBN Telephone Line
- Check if your phone is plugged into the correct port (VoIP or UNI-V).
- Restart your modem/router and wait for it to establish a connection.
- Contact your internet provider if issues persist.
2. Poor Call Quality or Dropped Calls
- Ensure a stable internet connection with adequate bandwidth.
- Use a high-quality VoIP-compatible telephone for better performance.
- Minimize network congestion by avoiding excessive internet usage during calls.
3. Devices Not Working After NBN Migration
- Some older devices, like fax machines and alarm systems, may require updates or replacements.
- Consider an NBN-compatible VoIP service for essential communications.
People Also Ask (FAQs)
Q1: Can I Use My Existing Landline Phone on NBN?
Yes, most standard landline phones work with the NBN if connected to a VoIP-enabled modem or an NBN connection box with a UNI-V port.
Q2: Do Cordless Phones Work with NBN?
Yes, cordless phones are compatible with NBN if they are plugged into a VoIP-enabled modem/router.
Q3: What Happens to My Security Alarm on NBN?
Many traditional security alarms are not compatible with NBN. You may need to upgrade to an NBN-compatible model or use a mobile-based monitoring service.
Q4: Can I Keep My Existing Phone Number on NBN?
Yes, in most cases, you can port your existing phone number to the NBN service, but check with your provider to confirm availability.
Key Takeaways
- The NBN Telephone Line supports most landline phones but requires VoIP or UNI-V port connectivity.
- Some older devices, such as fax machines and security alarms, may require upgrades.
- Ensuring a stable internet connection is key to maintaining high call quality.
- Contact your service provider for troubleshooting and device compatibility concerns.

Conclusion
The transition to the NBN Telephone Line has changed how Australians connect their landline phones and essential devices. While most standard phones are compatible, some older systems—like medical alarms, fax machines, and EFTPOS terminals—may require upgrades or alternative solutions. Ensuring a stable internet connection and using VoIP-supported equipment will help maintain call quality and functionality.
If you’re experiencing issues or need expert assistance with NBN telephone line setup, visit Value Services for professional support.