Introduction
By January 2027, the UK's traditional landline network, the Public Switched Telephone Network (PSTN), will be permanently switched off. This marks the end of an era for analogue telephony and the beginning of a fully digital communication future.
The migration to digital voice services like VoIP (Voice over Internet Protocol) is already underway, with over two-thirds of UK landlines upgraded. But many homes and businesses remain unprepared. From alarm systems to payment terminals, countless devices rely on legacy PSTN and ISDN lines and they will stop working unless upgraded.
What Is Happening?
In November 2017, the UK telecoms industry announced the retirement of legacy networks including analogue PSTN and ISDN (Integrated Services Digital Network). These decades-old systems underpin traditional landlines and many connected devices.
The Digital Transition
- • All voice calls will move to digital networks using Voice over IP (VoIP)
- • Landlines will connect via broadband, not copper wires
- • Full switch-off deadline: January 2027
Why Is This Happening?
The PSTN has served the UK for over 150 years but it’s now obsolete. Spare parts are no longer manufactured, repairs rely on scavenged components, and extreme weather increasingly disrupts service.
Key Drivers for Change
- • Network decay: Over 2,600 major PSTN outages in 2024/25 (Ofcom)
- • Better quality: Crisper calls, fewer dropped connections
- • Improved security: Built-in scam call blocking and encrypted voice transmission
- • Energy efficiency: Digital networks consume less power than legacy systems
Progress & Timeline
Over two-thirds of UK landlines have already transitioned to digital voice services. The migration is happening in phases, with full completion required by January 2027.
Devices Affected by the Switch-Off
It’s not just phones. Many critical systems rely on PSTN/ISDN lines and will fail unless upgraded:
Home Devices
- • Telecare and medical alarms
- • Burglar and fire alarms
- • Door entry systems
- • Fax machines
Business Systems
- • Payment terminals (EPOS)
- • Lift emergency phones
- • Intercoms and PA systems
- • Legacy phone systems (PBX)
Support for Vulnerable Users
If you or someone in your household relies on telecare, medical alarms, or emergency call systems, don’t wait for your provider to contact you - get in touch with The Zero Group today. We specialise in seamless, safe migrations for vulnerable users and ensure all connected devices remain fully operational after the PSTN switch-off.
How We Support You
- • Free site visits: Our engineers will assess your setup and ensure compatibility
- • Battery backup solutions: Keep critical systems running during power or broadband interruptions
- • Device testing & migration: We’ll test and upgrade your telecare, alarms, and emergency lines
- • Priority service: Vulnerable customers receive fast-tracked support and dedicated guidance
At The Zero Group, we work closely with local authorities and care providers to protect those who rely on life-critical phone-connected services. Contact us now to schedule your free vulnerability assessment and ensure you’re protected before 2027.
What Businesses Need to Do
At The Zero Group, we’re advising all business customers to act now. You need to review your current infrastructure to determine if any devices rely on legacy PSTN or ISDN networks.
Our Recommended Steps
- 1. Partner with us: Let The Zero Group conduct a full audit of your voice and data infrastructure
- 2. Upgrade your systems: Migrate to our secure, scalable VoIP and IP phone solutions
- 3. Ensure compatibility: We’ll test and upgrade all connected devices like EPOS, alarms, and intercoms
- 4. Future-proof your business: Benefit from enhanced reliability, security, and lower running costs
Key Benefits of the Digital Switch
Improved Reliability
Digital networks are less prone to weather damage and hardware failure.
Enhanced Security
Built-in scam call blocking and encrypted voice transmission.
Cost Efficiency
Lower maintenance costs and bundled digital services.
Future-Proofing
Scalable infrastructure ready for next-gen communication tools.
Final Thoughts
The PSTN switch-off isn’t just a technical update, it’s a critical infrastructure shift. Whether you’re a business with legacy phone systems or rely on connected devices like EPOS or alarms, now is the time to act.
At The Zero Group, we specialise in seamless digital migrations. From VoIP deployment to device compatibility testing, we ensure your business stays connected, compliant, and protected.
Ready to Future-Proof Your Business Communications?
Don’t risk downtime, lost sales, or safety issues. Let The Zero Group guide your digital voice migration with a free infrastructure audit.
Schedule Your Free Audit