The complete switch off of the Public Switched Telephone Network (PSTN) and Integrated Services Digital Network (ISDN) will be taking place in January 2027.

And coming at the end of 2025 will be the stop-sell: the complete discontinuation of sales and installations of analogue phone systems, and all connectivity products that rely on the old, copper PSTN or ISDN phone lines.

If you’re not ready for what’s next then don’t worry, you’re not alone. There are still thousands of businesses connected via copper and without a plan in place to either mediate in the interim or future-proof over the long term.

This could pose a significant risk to organisations that haven’t planned for the move.

To address this pressing issue, we've created a useful guide that covers everything you need to know and the alternative technologies that could be used to futureproof your services, including a way to delay the potential move to digital voice.

1. Understand the Impact & Conduct an Audit

First, it's essential to understand how the switch off will affect your business. PSTN and ISDN lines are being replaced by digital alternatives like Voice over Internet Protocol (VoIP). This change means that any devices relying on these old networks will need to be upgraded. Do you have traditional phone connections for inbound calls, a fax machine, a lift in your building with alarms or comms systems? These could all be impacted. Conducting a thorough audit of your current telephony and technology will help you plan appropriately, and your connectivity provider should be able to help you with this.

2. Explore an interim option

If you’re not ready to move to Digital Voice and upgrade your hardware, our customers can still prepare for the 2027 Switch Off with an alternative service called Metallic Path Facility (MPF).

Unlike other providers, TalkTalk Business offers voice services via MPF. This technology utilises the existing copper wires, connecting directly from our equipment in the Openreach Telephony exchanges to our customers’ premises. This ensures a smooth connection for standard (i.e., non-VoIP-compatible) phones to our own telephony switches.

TalkTalk Business's MPF voice services are therefore unaffected by WLR stop-sell or withdrawal in 2025, which means that we can continue to offer broadband and fibre to the Cabinet (FTTC) with MPF.

Your PSTN service could be migrated to MPF seamlessly giving you more time to plan and implement your digital strategy to move onto Digital Voice, when you’re ready.

3. Explore Digital Alternatives

Research and choose digital alternatives that suit your business needs. VoIP is a popular choice, offering flexibility and cost savings. Other options include cloud telephony and SIP trunking, which can provide enhanced features and scalability that support your business goals. The right solution for you will depend on how complex your requirements are.

4. Upgrade Your Infrastructure

Ensure your internet connection is robust enough to handle the increased traffic from digital telephony. You might need to upgrade to a higher bandwidth or more reliable connection to support VoIP and other digital services. In some instances, a traditional broadband solution may not be suitable and you may need to explore DIA or a leased line solution.

5. Exploring Digital Solutions? Then you Must Implement New Hardware

Unfortunately, your old technology that worked on PSTN & ISDN may not support your new digital solution and you will need to invest in new hardware that can enable digital communication. This might include VoIP phones, routers, and other network equipment.

You should consider partnering with a connectivity provider that can also support you in your identifying your requirements to ensure you’re getting expert advice and bang for your buck. Moving to a cloud-based digital solution will more than likely mean lower upfront costs or capex investment, as most will be delivered on a monthly subscription basis.

6. Plan for the Future

Finally, create a long-term plan to regularly review and update your connectivity systems. Technology is constantly evolving, and staying proactive will help your business remain competitive and efficient. By following these steps, your business can smoothly transition away from PSTN & ISDN and move towards a digital solution ensuring continued efficiency and competitiveness in the digital age. Don't wait until the last minute – start preparing today. Click here to read a more detailed guide to the PSTN & ISDN switch off.