What Is the Big Switch Off?
The Big Switch Off is the permanent shutdown of the UK’s analogue telephone network, the Public Switched Telephone Network (PSTN), on 31 January 2027.
The PSTN is the copper-wire network that has carried Britain’s phone calls for over a century. Every traditional landline, every fax machine, and every ISDN phone system runs across it. So do many things you might not expect: card payment terminals, fire and burglar alarms, lift emergency lines, CCTV systems and door entry panels.
When the PSTN goes, everything that depends on it stops working. Openreach has confirmed the deadline is fixed and will not move again. Any business still relying on analogue lines needs a migration plan, and with the deadline now under seven months away, that plan needs to happen soon. For the full step-by-step guide, see our PSTN and landline switch-off overview, or get a quote to start your migration.
When Is the Switch Off Happening?
The full PSTN shutdown completes on 31 January 2027, but for many businesses the practical deadline is earlier:
- September 2023: Openreach stopped selling new analogue lines and ISDN nationwide (the “stop sell”)
- May 2024: The original December 2025 deadline was extended to January 2027 to allow safe migration of vulnerable users
- Throughout 2025-2026: Local exchanges are being migrated in phases, so some areas lose analogue service before the national deadline
- 1 January 2026: Legacy line rental moved to 90-day rolling contracts
- During 2026: Wholesale prices for legacy lines rise sharply in three stages (more on this below)
- 31 January 2027: The PSTN is switched off permanently
Openreach has been clear the deadline cannot slip again. Their view is that the ageing copper network is now a bigger risk than the migration itself: major incidents on the PSTN rose 45% in a single year, and a single incident can knock out 500 or more lines at once.
Some communications providers set their own earlier cut-off dates, so don’t assume you have until January 2027. If your provider hasn’t contacted you about migration, that’s a red flag in itself.
Why Is the PSTN Being Switched Off?
The short answer: the network is over 100 years old and falling apart.
The copper PSTN was engineered for a world of rotary dial phones. The parts to maintain it are increasingly difficult to source, the engineers who know how to fix it are retiring, and the failure rate is climbing every year. According to Openreach, the analogue network is now obsolete, harder to maintain, and significantly more expensive to run.
Meanwhile, the replacement, digital voice services running over broadband, is cheaper to operate, more reliable, and far more capable. The UK is following the same path as most developed countries: the Netherlands, Estonia and others have already completed their analogue switch-offs.
This is part of a wider upgrade. Openreach is investing £15 billion in full fibre broadband, and retiring the copper network is a key part of moving the country onto modern digital infrastructure.
What Happens If You Do Nothing?
This is the question that matters most, and the answer is blunt.
If you take no action before your line is migrated or switched off, your provider may default you onto a basic emergency-only fallback service. That means your number can reach 999, and nothing else. No inbound calls from customers. No outbound calls to suppliers. Your business number effectively goes dark.
Before that happens, you’ll be paying steadily more for a service with a confirmed shutdown date, because Openreach is deliberately raising legacy line prices to push the final migrations through.
And it’s not gradual. When your exchange is migrated, analogue service ends. Businesses that leave it until the final weeks risk joining a last-minute rush, with every provider’s installation calendar full, hardware in short supply, and no room for the porting process to run smoothly.
Roughly 2.8 million lines were still on the PSTN at the start of 2026, over half a million of them serving business premises. That’s a lot of businesses competing for engineer availability in the final months. Moving early isn’t just safer, it’s the only way to guarantee a smooth transition on your own timetable.
It’s Not Just Phones: What Else Is Affected
The most dangerous misconception about the Big Switch Off is that it only affects desk phones. In reality, decades of equipment has been quietly wired into analogue lines:
- Card payment terminals – older PDQ machines that dial out over a phone line
- Fire and intruder alarms – many alarm panels signal to monitoring centres via PSTN
- Lift emergency lines – over 12,000 lift lines were still on copper at the start of 2026
- CCTV systems – legacy setups using phone lines for remote monitoring
- Door entry and gate systems – intercoms that dial a phone number
- Fax machines – still common in some industries
- Franking machines – older models connect via analogue line
- ISDN phone systems – ISDN2 and ISDN30 run on the same copper network and die with it
- ADSL and FTTC broadband – older broadband products delivered over the copper network are being withdrawn too
For sectors like construction, hospitality and property management, the alarm, lift and payment terminal issue is often bigger than the phones themselves. A hotel with an analogue fire alarm line or a property firm managing buildings with copper lift lines has a compliance and safety problem, not just a telecoms one.
The fix is an audit: walk through everything in your premises that plugs into a phone socket, and check with your suppliers whether each device has a digital-ready replacement or upgrade path.
Legacy Line Prices Are Rising Right Now
If the deadline alone isn’t persuasive, the pricing should be. Openreach has confirmed a tiered set of wholesale price increases on legacy line rental designed to make staying on copper uneconomic:
| Date | Wholesale price increase |
| 1 April 2026 | +20% |
| 1 July 2026 | +40% |
| 1 October 2026 | Further +40% |
By this autumn, the cost of a legacy analogue line will have effectively doubled compared to the start of the year. In many cases it’s already cheaper to be on a modern digital service than to keep paying for the old line.
In other words: doing nothing isn’t the cheap option. It’s the expensive option with a hard stop at the end.
What Replaces Your Landline?
The replacement for analogue phone lines is VoIP, Voice over Internet Protocol. Instead of your calls travelling down a dedicated copper wire, they travel over your broadband connection as data.
For a typical small business, a modern hosted VoIP system means:
- Desk phones that plug into your network (or softphone apps on computers and mobiles)
- A cloud phone system managed through a web portal instead of a box on the wall
- Your existing numbers, ported across so nothing changes for your customers
- Calls over broadband, ideally full fibre (FTTP) or SoGEA where fibre isn’t available yet
At ATS Connection we provide business VoIP built on the Xelion platform, a fully featured cloud phone system that handles call routing, voicemail-to-email, mobile apps, call recording and hunt groups as standard. It’s the same system we use ourselves, and we’ve migrated businesses across West Sussex from ageing analogue and ISDN setups onto it, including multi-site companies and businesses with complex call-handling needs.
If your broadband also runs on the old copper network (ADSL or FTTC), the switch is the right moment to upgrade connectivity at the same time. One project, one provider, everything future-proofed together.
The Benefits of Switching to VoIP
The Big Switch Off is forcing the move, but for most businesses VoIP is a genuine upgrade rather than a like-for-like swap:
Lower running costs. No line rental on copper pairs, cheaper call rates, and free calls between sites and colleagues. Most businesses save money compared to their old analogue or ISDN bills.
Work from anywhere. Your business number rings on your desk phone, your laptop and your mobile. Staff working from home or on site answer calls exactly as if they were in the office, a game-changer for trades, construction and field-based teams.
Scale up and down instantly. Adding a new user is a few clicks, not an engineer visit and a new line installation. Seasonal businesses can add lines for busy periods and remove them after.
Professional call handling. Auto-attendants (“press 1 for sales…”), hunt groups, call queues, out-of-hours routing and voicemail-to-email. Features that used to require an expensive on-premise phone system come as standard.
Business continuity. If your office loses power or internet, calls automatically divert to mobiles. With an analogue line, a fault means silence until an engineer arrives.
Call insights. See call volumes, missed calls and response times. Useful data you simply never had with analogue lines.
Will You Lose Your Phone Number?
No. This is the most common worry we hear, and it’s the easiest to put to rest.
Your existing numbers, including long-standing local numbers your customers have known for years, can be ported to your new VoIP service. The porting process is handled between providers and typically takes 10-15 working days. There’s no need to reprint stationery, update signage or change your website.
The key is to never cancel your old line before the port completes. Cancelling first can mean losing the number permanently. A competent provider will manage the sequencing for you so there’s no gap in service: your new system goes live, the number ports across, and only then does the old line get ceased.
How to Prepare: A Step-by-Step Checklist
Here’s the practical path from “still on analogue” to “sorted”:
1. Audit everything connected to a phone line. Phones, alarms, lifts, card machines, door entry, fax, CCTV. List every device and every line. This is the step most businesses skip, and it’s where the nasty surprises hide.
2. Check your broadband. VoIP needs a reliable internet connection. If you’re on ADSL or FTTC, plan the broadband upgrade alongside the phone migration. Check full fibre availability for your postcode.
3. Count your users and map your call flows. Who needs a handset? Who’s fine with an app? How should incoming calls route: reception first, then a hunt group? Out-of-hours to a mobile? This shapes the system design.
4. Choose your VoIP provider and system. Look for business-grade platforms, UK support, and a provider who handles number porting and installation end to end.
5. Deal with the non-phone equipment. Contact your alarm company, lift maintainer and payment provider about digital-ready upgrades. Most have well-established migration paths now, but lead times vary.
6. Schedule the migration. Ideally months before the deadline, not weeks. Number porting, hardware delivery and any broadband installation all have lead times that compound if left late.
7. Test everything, then cease the old lines. Only cancel legacy lines once numbers have ported and every dependent device is confirmed working on its new connection.
If that list feels like a lot, that’s what we’re here for. We run this entire process for clients as a single managed project, from audit through to the final line cease.
How Long Does Switching Take?
For a straightforward small business, a handful of users, decent broadband already in place, the switch can be completed in 2-4 weeks, most of which is waiting for number porting.
Add broadband upgrades, multiple sites, or dependent equipment like alarms and lift lines, and a realistic timeline is 1-3 months to do everything properly without disruption.
That’s exactly why the time to start is now, not December. Businesses that begin the process in the second half of 2026 will be competing with hundreds of thousands of others for engineer appointments, hardware and porting slots. Starting now means you choose the timetable; starting late means the timetable chooses you.
Frequently Asked Questions
What is the Big Switch Off in the UK?
The Big Switch Off is the permanent retirement of the UK’s analogue Public Switched Telephone Network (PSTN) on 31 January 2027. All traditional landlines, ISDN phone systems and services running over the copper phone network will stop working and must be replaced with digital (VoIP) alternatives.
When exactly will my landline stop working?
The national deadline is 31 January 2027, but exchanges are being migrated in phases and some providers have set earlier dates. Your line could be affected before the final deadline, so check with your provider now rather than assuming you have until 2027.
Will the PSTN switch off be delayed again?
No. The deadline was moved once, from December 2025 to January 2027, to protect vulnerable users during migration. Openreach has confirmed that work is complete and the January 2027 date is fixed.
Does the switch off affect broadband too?
Yes, partly. ADSL and FTTC broadband run over the same copper network and are being withdrawn alongside the PSTN. Full fibre (FTTP) and SoGEA connections are unaffected; they’re the replacements.
Can I keep my business phone number when I switch to VoIP?
Yes. Numbers are ported to your new VoIP provider, typically within 10-15 working days. Don’t cancel your old line until the port has completed, or you risk losing the number.
What happens to my card machine and alarm system?
Any device that connects via an analogue phone line, such as card terminals, fire and intruder alarms, lift lines and door entry systems, needs a digital upgrade before the switch off. Contact each supplier about their migration path, and do it early as lead times vary.
Is VoIP more expensive than a landline?
Usually the opposite. Most businesses pay less per user per month for VoIP than they did in line rental and call charges, and legacy line prices are rising steeply through 2026 anyway. VoIP also removes the cost of maintaining an on-premise phone system.
Do I need new phone handsets for VoIP?
Not necessarily. Modern VoIP systems work with dedicated IP desk phones, softphone apps on computers, and mobile apps. Some existing handsets can be reused with adapters, though for most businesses new IP handsets or apps are the cleaner option.
What if my internet goes down? Will I lose my phones?
Calls can automatically divert to mobiles or another site if your connection fails, which is more resilient than analogue ever was: a copper line fault meant no calls at all until an engineer fixed it. A well-designed VoIP setup includes failover from day one.
What should businesses in West Sussex do first?
Start with an audit of every line and every device connected to one. If you’d rather not do that yourself, we offer a free switch-off readiness check for businesses across West Sussex. We’ll identify what’s affected and map out the migration for you.
Get Switched Before the Deadline
The Big Switch Off isn’t a maybe. It’s a fixed deadline with rising costs for anyone who waits. The businesses that come out of it best are the ones treating it as an opportunity: modern phones, better call handling, lower bills and a system that works wherever your team does.
At ATS Connection we’ve been moving West Sussex businesses onto our Xelion-based VoIP platform ahead of the deadline, handling the audit, the number porting, the hardware and the broadband, all as one managed project.
Book your free Big Switch Off readiness check:
- Call us on 01903 255 159
- Email hello@atsconnection.co.uk
We offer:
- Free switch-off readiness audits for local businesses
- Business VoIP phone systems
- Business broadband and connectivity upgrades
- Managed IT support so your whole setup is covered by one team
Don’t wait for the last-minute rush. Get ahead of the deadline while there’s still time to do it properly.