BT ISDN Switch Off 2025… are you ready?

What is the BT ISDN Switch Off and how will impact your business?


BT are switching off the PSTN and ISDN networks for good, starting with a cease of new supply by 2020 and moving to a full migration to IP before 2025. The BT ISDN switch off could affect thousands of businesses in the near future, especially those unaware of BT’s phasing out of ISDN technology.

If you work within the industry, the switch to IP technology makes perfect sense. Traditional phone lines are a legacy technology with high maintenance costs and alot of drawbacks. ISDN was originally designed to allow both voice and data services to be delivered simultaneously however, just as we have moved on from the limited functionality of brick sized mobile phones, the introduction of high speed internet access means ISDN technology is no longer relevant in the average work place.

How do we prepare for the BT ISDN Switch Off?

In Short, by 2020 you will no longer be able to order ISDN services and in real terms you have two options to consider.

  • SIP Telephone Lines (SIP Trunk)
  • Hosted Telephone System (Cloud Telephony)

If you currently have a traditional ISDN/PSTN telephone system then is is good practice to look into an alternative. Plan ahead and you may actually find you want to migrate sooner rather than later. Although the official switch off is 2025, as we get closer the other options will only become more costly.

Remember – Businesses will be unable to buy new phone systems that use ISDN and PSTN after 2020 and upgrading your current system to support these technologies is probably going to be very costly, and you certainly don’t want your business to invest in old technology now.

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