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The 2025 Switch Off, which is the end of older telephone and broadband infrastructure, is set to affect over a million businesses across the UK.

In this guide, we've answered the following questions:

BT has announced it will end-of-life its Integrated Services Digital Network (ISDN) by 2025. ISDN is used by over one million UK businesses and the closure of the ISDN network means that businesses have no choice but to update their communications systems.

In this blog, we will answer the key questions around the switch off and the next steps to a future-proofed solution.

What is ISDN?

The Integrated Services Digital Network is a communication standard that allows you to transmit voice and data over a digital line. It is a popular communication technology used to facilitate telephone systems in businesses across the UK.

ISDN will be switched off in 2025

Why is ISDN being switched off?

Since being introduced by BT in 1986 connectivity has advanced significantly. New digital technologies have been introduced and ISDN is now dated technology. The introduction of services like SIP and FTTP has allowed businesses to better connect their people.

The ISDN switch off will pave the way for new, better solutions that are equipped to deal with modern communication.

When will the switch off happen?

BT won’t be issuing any new orders from 2023 followed by a complete withdrawal of all ISDN2 and ISDN30 lines in 2025, meaning any businesses currently using either solution will need to find a replacement before that time.

The 2025 Switch Off Hub contains all the latest information on the big switch off. From tranches and stop sell dates to alternative broadband and telephony solutions, the hub is the best place to get the latest information.

Visit the 2025 Hub

Speak to an impartial consultant to get advice on your 2025 Connectivity and Voice strategy. Book your FREE consultation to speak to an expert about the 2025 switch off and what it means for your business.

How do I know if I have an ISDN line?

If you're a Chess customer and you are unsure if you're using ISDN please contact your account manager or email us.

Over 1 million businesses use ISDN

What other options do I have?

If you're making the switch from ISDN you'll need to find a new solution that will allow you to remain connected to your customers and people.

Save up to 30 percent with VOIP

Cloud Telephony is a voice & data solution that allows you to communicate freely via the internet, without the need for a copper wire. Cloud Voice helps you work better, together. It helps businesses improve efficiency and gives businesses the tools to communicate with customers seamlessly to improve customer service. What's more, you could also save money by switching.

Learn more about Cloud Voice

How do I stay up to date on the ISDN Switch Off?

We've put together a 2025 Switch Off Hub that contains all the latest information on the big switch off. From tranches and stop sell dates to alternative broadband and telephony solutions, the hub is the best place to get up to date information

Visit the 2025 Hub

If you'd like to talk to a 2025 expert, you can also book a consultation with one of our team. 

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