BT ISDN Switch Off

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BT has announced that you can purchase ISDN lines up to September 2023 instead of the original date, 2020. There will be a forced migration phase between April and December 2025 (these dates represent the nationwide stop-sells, different areas may have different stop-sell dates).

Even though you have been given a few more years to be able to purchase more ISDN lines, we still advise that if your telephony contract is up for renewal you start exploring alternatives as ISDN is old technology and will soon be obsolete. If your contract will still be live after 2023 you should ensure you have enough ISDN phone lines to cope with your growth plans.

Why is ISDN being switched off?

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, it will be quite expensive to run all of the different networks.

Alternative options to ISDN

You have a few options but the main 2 are Sip and Hosted VoIP systems:


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 at 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.

To find out more about SIP: click here

Take a look at our ISDN to SIP migration checklist: click here

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)

Learn more about VoIP: click here

Read more about your alternative options: click here

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) 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 ChecklistView 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.

Want to talk to an expert?

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.

Contact us now: 0330 222 0330 | | Contact us page | fill out the form below

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

See Also

As Always, our Advice is Free

Need help deciding the best steps forward?

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