On 31 January 2027, the UK’s telephone network switches off. Every ISDN line, analogue phone line and PSTN-dependent service stops working. Openreach has confirmed: no extension, no grace period.
The deadline is fixed. 31 January 2027. If your business has not migrated, your phone lines, alarms and broadband will simply stop.
It is not just phones
This is where businesses get caught out. The switch-off affects everything that plugs into a phone socket:
- Intruder alarms and fire alarms — many dial a monitoring station over a phone line
- Lift emergency phones — legally required, often on an analogue line
- Payment terminals — some older card machines still use PSTN
- CCTV remote monitoring — often an analogue connection
- Door entry systems — intercoms that dial a phone number
- Fax machines — still used in healthcare, legal and manufacturing
- Telecare alarms — critical for care homes
What replaces it?
Phone systems move to SIP trunking or hosted VoIP — calls over your internet connection instead of copper.
Alarms and devices move to 4G/5G cellular communicators or IP adapters. More reliable than the old phone line.
Broadband on ADSL moves to SoGEA (no phone line needed) or full fibre where available.
Why waiting is risky
Engineer availability — every business that has not migrated will be trying to book at the same time. Lead times are already stretching.
Hardware supply — IP phones, alarm communicators and network equipment will be in short supply near the deadline.
Cost — plan ahead and you choose the best solution at fair prices. Scramble at the last minute and you pay rush premiums.
Businesses that act now choose. Businesses that wait accept whatever is left.
Five things to do this month
1. Audit your lines
Find out how many PSTN and ISDN lines you have, and what each one does. Ask your phone provider, alarm company and broadband supplier.
2. Check your broadband
ADSL will stop working. Move to SoGEA or FTTP.
3. Talk to your alarm company
Ask whether your alarms and lift phones are PSTN-dependent. Digital communicator upgrades are straightforward.
4. Review your phone system
If you are on ISDN, you need SIP or hosted VoIP. Systems over ten years old may not support SIP. Modern platforms like Splicecom, Wildix or Teams Phone are typically cheaper than ISDN.
5. Start number porting early
Your numbers can almost always be kept. Porting takes 10–15 working days. Start early to avoid gaps.
The upside
SIP is cheaper than ISDN. Cloud phone systems give you mobile apps, Teams integration, call recording and auto-attendant — features that used to be enterprise-only.
Migrate now and it is an upgrade. Wait and it is a scramble.
Not sure what the switch-off means for your business? We offer a free audit of your current lines and equipment.
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