BT ISDN Switch Off

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(Updated ISDN news 27.01.2020) BT announced in 2015-16 that from 2020 you will no longer be able to purchase ISDN lines with a target date of 2025 for a switch off date. They have now revised that date and have stated that you can purchase ISDN lines up to September 2023. There will be a forced migration phase between April and December 2025.

What happens if I have ISDN?

Even though you have been given a few more years to be able to purchase more ISDN lines, it doesn't change the fact that it is old technology and will soon be obsolete. We advise that if your telephony contract is up for renewal that you start exploring alternatives, now.

If your contract is still live for a few more years, just ensure you have enough ISDN phone lines to cope with your growth plans before you can no longer purchase any more (2023).

Why are they doing it?

BT is giving a little tip of the hat in acknowledgement that communication has changed and that IP (Internet over Protocol) is the best next step for businesses to take; so, they have decided not to invest any more time and money into a technology that won’t enhance the business world.

Also, let’s face it, it will be quite expensive to run all of the different networks. By converging all services to IP, they only have to maintain one.

Alternative options to ISDN

You have two main alternatives:


SIP uses virtual phone lines rather than physical lines like ISDN. It is the best alternative solution if you have an on-premise phone system.

This is mostly down to the flexibility it gives you, the speed in which you can add/remove lines, the quality of the calls and the lower call costs.

You may not even have to change your existing phone system as most systems are compatible with SIP.

Learn more about SIP Phone Lines

Hosted VoIP

If you have ISDN lines and don’t want to commit or retain an on-premise phone system, then a Hosted IP phone system would be the best solution.

Hosted IP Phone Systems use your internet lines but you effectively rent a phone system. It is a great option for those who want the functionality and scalability of a phone system with no extra maintenance charges. (View Benefits of hosted telephony here)

View our Research on the Phase-out of ISDN and the Alternative Solutions

We have a selection of resources available (for free) on the phase-out of ISDN.

View all Related Resources

Is it easy to migrate across to Hosted VoIP or SIP?

With the right provider – yes. You’ll be able to port and retain your numbers over. The whole migration (depending on some factors like the number of sites) it can take as little as 3 weeks.

What do I need to consider with the migration?

There are a few things you need to consider before you migrate; so check out our migration checklists:

View our ISDN to Hosted Migration Checklist

View our ISDN to SIP Migration Checklist

Okay, I need to start talking to someone about this!

We’d be happy to give you some advice as to when you need to make the switch and any more considerations to make; as always, our advice is free.

See Also

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Researching Alternatives to ISDN?

We have over 15 resources on ISDN and your options. They are all free to download. Topics include:

Plus many more...

View all Related Resources
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