The 2027 phone switch-off: what your business must do, and what VoIP now makes possible
By Jera IT
Originally published August 2026. Refreshed November 2026: the deadline is now 31 January 2027, under three months away, so we've added the migration paths and what a modern phone system can do once you've moved, including AI call answering.
If your business still runs on traditional phone lines, there’s a deadline you can’t ignore: the UK’s old landline network is being switched off. Leave it too late and you risk losing your lines with no fallback. The good news is that what replaces them can do far more.
The short answer: move your phones to VoIP before 31 January 2027, and check everything else that uses a phone line while you’re at it.
What’s being switched off
The traditional PSTN and ISDN network, the system that has carried UK phone calls for decades, is being retired by 31 January 2027 (GOV.UK). Once it’s gone, anything that depends on it stops working, and that means more than handsets: alarms, door entry systems, lift emergency phones, card machines and fax lines.
Your migration options
| Option | Best for | Notes |
|---|---|---|
| Hosted (cloud) VoIP | Most small and medium businesses | Desk phones, apps and softphones; no phone system on site |
| Microsoft Teams Phone | Businesses already on Microsoft 365 | Calls in Teams on laptops, mobiles and desk phones |
| SIP trunks | Businesses keeping an existing phone system | Connects your current system to internet calling |
| Digital line | Very small sites, or a single line for an alarm | A like-for-like replacement over broadband |
Whichever you choose, you can keep your existing numbers. Make sure your broadband is reliable and has a backup, because your phones will now depend on it.
Why this is good news
- Calls follow your team to any device, wherever they work.
- Add or remove lines in minutes, not weeks.
- Call routing, voicemail-to-email, call recording and reporting usually come as standard.
- It is often cheaper than your current line rental, and we’ll compare the two for you before you switch.
What modern phones now make possible
AI agents that answer and make calls
With VoIP, AI voice agents have become practical for small businesses:
- A virtual receptionist answers calls at any hour, deals with common questions and puts callers through to the right person.
- Appointment booking puts bookings straight into your calendar.
- Sales call handling captures details and qualifies enquiries, then passes good leads to your team straight away.
- Outbound calls handle appointment reminders and renewal check-ins.
The result: fewer missed calls, and staff freed from routine calls. Set them up with care: tell callers they’re speaking to AI, give them a route to a person, and check the marketing rules before using AI for sales calls (automated marketing calls need specific prior consent, and live ones must be screened against the TPS: see the ICO’s telephone marketing guide). See our AI Receptionist Agent ↗, which answers calls and web enquiries day and night, and the AI Lead-Response Agent ↗, which answers enquiries in seconds and books the appointment. The catch: with Jera IT support your first agent is built, supported and maintained free, but you pay for the AI it uses.
Proving who’s calling
Caller ID can be faked and AI can clone voices, so modern phone systems increasingly verify callers with one-time codes:
- When a customer calls, send a code by SMS or WhatsApp to the number on file and ask them to read it back before discussing their account.
- When you call a customer, offer to send a code so they know it’s really you.
- For staff, agree that genuine IT support never asks for passwords or MFA codes, and verify any request that changes access or money.
For high-risk changes like bank details, combine a code with a callback to a known number. More in are VoIP phones secure?.
Don’t wait for the deadline
The businesses that struggle are the ones that leave it until their line is cut off and scramble. Moving now means a calm, planned switch: you keep your numbers, the alarms and door entry are sorted, and there’s no gap in service. Two months of planning beats a weekend of panic.
Make the switch on your terms
We’ll find what else depends on your old lines and move you to a modern phone system without the drama, and because your calls then run over VoIP, we can deploy AI voice agents in your business too. See our telecoms service, or book a call to plan your switch before 31 January.
Frequently asked questions
When is the UK phone switch-off?
The old PSTN and ISDN landline networks are being switched off by 31 January 2027 (BT and Openreach's date; government guidance says by January 2027). Many areas have already moved, and new PSTN and ISDN lines haven't been sold since September 2023.
What happens to my business phone line?
Phone lines that rely on the old landline network will stop working. Calls will instead run over internet connections, using VoIP. You can keep your existing phone numbers when you move.
What else is affected by the switch-off?
Anything that uses a traditional phone line: alarm systems, door entry, lift emergency phones, card payment terminals, franking machines, fax lines and some monitoring equipment. Check each one with its supplier before your line is switched.
What are the migration options for business landlines?
The main options are a hosted (cloud) VoIP phone system, Microsoft Teams Phone, SIP trunks connected to an existing phone system, or a simple digital line for very small sites. The right choice depends on how many users you have and how they work.
Can AI answer my business calls?
Yes. With a VoIP system, AI voice agents can answer calls at any hour, answer common questions, book appointments, qualify sales enquiries and transfer callers to staff. Set them up to say they're AI, and to verify callers before discussing accounts or making changes.
