BT is permanently switching off the UK's entire ISDN and PSTN network. When it goes, any business still relying on traditional landlines or an older phone system will lose service completely. There is no extension. There is no fallback. The deadline is fixed.
The good news: migrating to a modern cloud phone system is straightforward, affordable and often cheaper than what you're paying now — if you plan ahead.
Don't leave this too late. Engineer capacity and network migration slots fill up as the deadline approaches. Businesses that start now get a smoother transition, better choice and lower cost.
BT has confirmed this date will not move. Some exchanges are being switched off earlier as part of a rolling programme — your business may be affected sooner than you think.
Find out if your exchange is in an early switch-off area — contact us and we'll check for you.
If any of the following apply to your business, you need to act before January 2027:
If any of the above apply, you need a migration plan. The more items taht apply, the more complex your migration may be — and the earlier you should start.
Not sure what you have? Get in touch and we'll audit your current setup for free.
The consequences
On the day BT switches off your exchange, ISDN and PSTN services stop. Not gradually. Not with a warning. They stop.
Here's what that means in practice:
Incoming calls won't connect. Outgoing calls won't work. Clients, suppliers and staff who call your office number will get nothing.
If your internet connection is delivered over a copper phone line (ADSL or FTTC), it will also be affected.
Any PBX or office phone system connected to ISDN lines will become inoperable.
Fax machines, alarm systems, EPOS terminals and door entry systems that rely on a phone line will stop functioning.
Find out exactly what needs migrating. Before you can plan a migration, you need to know what you're migrating from. That means identifying every phone line, every system and every device in your business that uses the PSTN or ISDN network — including things that aren't obviously phones, like alarms and card machines.
We do this audit for you, free of charge, as the first step in our migration process.
Pick the cloud solution that fits your business. There's no single right answer — the best replacement depends on how your business uses its phones, how many lines you need, and how much you want to spend. The options are hosted VoIP, hosted PBX and SIP trunking. We'll explain the differences clearly and recommend the right one for your setup.
Get it done while you still have options. Migration capacity — engineers, installation slots, network porting windows — will tighten significantly as January 2027 approaches. Businesses that migrate now get first choice of provider, better pricing and a calmer transition. Those that wait until late 2026 will face higher costs, longer waits and fewer options.
Our migration service
We survey your current setup and identify everything that needs to migrate — including items you might not have thought of.
We explain your options in plain English and recommend the right solution for your business. No jargon, no upselling.
Your existing phone numbers transfer across. Clients and staff dial the same numbers they always have.
We're based in Edinburgh and available throughout your migration — not a national helpline you'll never reach.
Can I just wait and see what happens in January 2027?
+My exchange hasn't been switched off yet — do I still need to worry?
+How much does a VoIP migration cost?
+Will we lose service during the migration?
+We rent our office — is the migration our responsibility or the landlord's?
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The businesses that migrate early get the best choice of solution, the best pricing and the calmest transition. The businesses that leave it late pay more, wait longer and scramble. We've seen both — and the difference is significant.
Get in touch today for a free, no-obligation migration assessment. We'll tell you exactly what you have, what needs to change and what it will cost — usually within 24 hours.