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ISDN Switch Off

We are all familiar with the copper wire telephone network which has been in use since 1876. It has kept business communications going for years. But that is all about to change.

In 2025, the Public Switched Telephone Network (PSTN) is being switched off by BT Openreach. This means that everyone using PSTN-based services will need to move to another service before then.

This affects any businesses using ISDN or analogue phone lines. The Switch Off applies to both new installations and any extension of existing phone lines.

This is a major step towards the United Kingdom’s mass IP-network migration, with VoIP core networks set to replace all the legacy PSTN services in a few years’ time.

The PSTN Switch Off timeline

November 2017 – Switch Off announced

  • BT Openreach announced its intention to switch off the PSTN in 2025.

December 2020 – Salisbury Stop Sell

  • PSTN customers in Salisbury no longer able to purchase new ISDN or analogue lines or add new features to existing lines, where their premises are served by new access technology (such as FTTP or SOGEA).

October 2021 – The start of stop sell at telephone exchanges.

December 2022 – Salisbury End of Life

  • The PSTN network will be completely switched off in Salisbury.

December 2023 – UK Stop Sell

  • New ISDN lines or new features for existing lines will stop being available in the UK.

December 2025 – UK End of Life

  • The PSTN network will be completely switched off across the UK.

What to do if your business is affected

If your business is currently using ISDN or analogue telephone lines then you need to start planning your transition to alternative technology.

We can help you review the options and identify the business solution to replace your PSTN services.

In most cases, we recommend moving to Voice over Internet Protocol (VoIP), a solution that transmits voice calls and data using an internet connection. This is the future of telephony, and the PSTNN Switch Off is the ideal opportunity to embrace it.

Discover how we helped Brentwood Communications switch from ISDN to VoIP.

Call us on 0800 316 2970 or email to explore the solutions for your business.

Please note that if you are an ITS customer then our team will be in touch to support your transition to alternative technology.

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