How will the PSTN switch-off impact your business?

The UK’s communications landscape is undergoing a major transformation. By January 2027, BT Openreach will completely decommission the Public Switched Telephone Network (PSTN) and Integrated Services Digital Network (ISDN). This milestone event – widely known as The Big Switch Off – will affect every business still relying on traditional landline infrastructure. 

If you’re wondering how this shift might impact your business, this article breaks down the changes, risks, and the steps you should be taking right now. 

What is the PSTN switch-off? 

The PSTN is the decades-old copper-wire phone network that has been the backbone of UK communication. While reliable, it is increasingly outdated, expensive to maintain, and unable to keep pace with modern digital demands. 

From 2027, the UK will move entirely to fibre-based, digital networks. All PSTN and ISDN services will cease to function, meaning businesses must transition to Voice over Internet Protocol (VoIP) or other digital alternatives to stay connected. 

Who will be affected? 

In short: everyone still using analogue phone lines. 

The switch-off impacts not just phone calls, but also any devices connected to PSTN or ISDN lines, such as: 

• Landline telephone systems 

• Broadband services (ADSL, ADSL2+, Fibre to the Cabinet) 

• Security and fire alarms 

• Payment systems (chip and PIN, POS machines) 

• Fax lines 

• Lift and emergency call systems 

Even if you’ve already moved your main communications online, you may still have legacy services that depend on copper lines. 

Key risks for businesses

Loss of connectivity

Without upgrading your phone system will stop working. Broadband services relying on copper lines will also be cut off, leaving your business offline. 

Operational disruptions 

From alarms to payment terminals, essential services tied to PSTN could suddenly fail – with major implications for safety, security, and customer service. 

Last-minute rush 

Waiting too long to migrate risks limited availability of suppliers, engineers, and equipment, as thousands of businesses scramble to switch over at the same time. 

Training gaps 

Moving to VoIP and digital platforms means new processes for your team. Without preparation, employees may struggle to adapt quickly, affecting productivity. 

The business case for switching early 

Although the switch-off may feel like a hassle, the benefits of moving to digital systems are significant: 

• Scalability – easily add or remove users as your business grows 

• Flexibility – access calls from desk phones, mobiles, or computers 

• Advanced Features – call forwarding, voicemail-to-email, video integration, and more 

• Cost Savings – VoIP solutions are often cheaper and priced per user 

• Future-Proofing – ensure your communications infrastructure can evolve with technology 

Rather than waiting for disruption, switching early positions your business for long-term gains. 

Practical steps to prepare 

Here’s a roadmap to make sure you’re ready before 2027: 

Audit your PSTN usage 

Identify all devices and services connected to PSTN or ISDN lines. 

Check internet capacity 

Ensure your broadband can handle VoIP traffic (ideally fibre with at least 20 Mbps download and 5 Mbps upload speeds). 

Explore digital alternatives 

Research VoIP, SIP trunking, or Unified Communications platforms that suit your business. 

Plan number porting 

Reassure your customers by keeping your existing phone number where possible. 

Test & train 

Trial your new system, iron out issues, and provide staff training to ease the transition. 

Supporting remote & hybrid teams 

For businesses with remote/hybrid workforces, the switch-off presents both challenges and opportunities. Remote employees may still rely on PSTN-based home broadband or analogue phones. Migrating to VoIP and digital platforms will ensure your teams stay seamlessly connected, no matter where they work. 

With features like mobile apps, video conferencing, and integrated messaging, digital systems actually enhance collaboration in flexible work models. 

Final thoughts 

The PSTN switch-off is not just an infrastructure change – it’s a catalyst for businesses to modernise, streamline, and future-proof their communications. 

Failing to act could mean disruption to your phones, internet, payment systems, and security. But planning early gives you the opportunity to adopt flexible, cost-effective, and feature-rich digital solutions that will serve your business for years to come. 

Get expert help with Moneypenny 

Still unsure where to start? At Moneypenny, we’re here to make the transition as smooth as possible. If you need support resetting your Moneypenny divert number, our Client Support team is just a call away on 0345 123 3700.