Business phone lines and the PSTN switch-off on 31 January 2027: what still runs on the old line, the replacement phone systems and how to move
Many small businesses — shops, trades, surgeries, offices and guesthouses — still run their phones on an analogue or ISDN line, and often a card terminal, an alarm, a lift phone or a door entry panel uses the same line. The UK's copper telephone network, the PSTN, is retired on 31 January 2027, and anything that depends on it needs to move to a digital service. This guide explains which devices typically rely on the old line, how to tell whether a line is still analogue or ISDN, and how the main replacements differ: a digital landline over broadband, a hosted VoIP or cloud phone system, and mobile-based setups. It covers what moving involves, from keeping the existing number and handsets to contract terms and battery backup in a power cut, and the questions worth asking a provider. Costs depend on the number of users and the features chosen, and some older equipment needs replacing.
The PSTN switch-off marks the end of an era for UK telecoms infrastructure. Many businesses have used the same copper-based phone lines for decades without a second thought, but the technology behind them is being phased out. Understanding what this means in practical terms helps business owners plan a smooth transition rather than facing a sudden disruption.
What does the PSTN switch-off mean for business lines?
The Public Switched Telephone Network, built on copper wiring, has carried voice calls across the UK for over a century. Openreach has confirmed that analogue and ISDN services will stop being supported, with the final withdrawal date set for 31 January 2027. For businesses, this means any phone line still running on traditional copper technology will eventually stop working unless it has been migrated to a digital alternative. The change is not optional, as the underlying network itself is being decommissioned rather than individual contracts being cancelled.
Which devices still rely on an old business phone line?
Many pieces of equipment quietly depend on the old copper network without businesses realising it. Card payment terminals using a phone line to process transactions, alarm systems that signal to monitoring centres, lift emergency phones, door entry intercoms and fax machines are common examples. These devices often sit outside the main telephone system, which means they can be overlooked during a general phone upgrade. Checking every piece of equipment connected to a phone socket is a necessary step before any switch-off deadline.
How can a business tell if its line is analogue or ISDN?
Identifying the type of line in use does not require specialist knowledge. The physical wall socket is one clue, since older analogue sockets look different from newer digital ones. The phone bill is another useful source, as providers typically list the service type, whether that is a standard analogue line, an ISDN2 or ISDN30 circuit. Finally, the equipment itself, such as an older PBX unit or a phone handset with a corded base station, can indicate how calls are being carried. When in doubt, contacting the current provider directly will confirm the exact setup.
What replacement phone systems are available for businesses?
Several alternatives have emerged to replace analogue and ISDN lines. Digital landlines delivered over broadband, often called Voice over IP for a single line, keep a familiar handset experience while using internet infrastructure. Hosted VoIP or cloud phone systems move the entire business phone system online, offering features like call routing, voicemail to email and multi-site connectivity. Mobile-based setups, where calls route through apps or SIM-based services, suit businesses with flexible or remote teams. The right choice depends on call volume, number of staff, and reliance on fixed-location equipment.
How does a business move its phone line to a new system?
Moving a business phone line involves several practical steps. Keeping the existing number is usually possible through a process called porting, which most providers support without charge. Compatible handsets may need replacing if they are not suited to VoIP or digital landline technology. Contract terms should be reviewed carefully, particularly around notice periods and early termination fees. Battery backup is another consideration, since digital phone systems rely on power and broadband, meaning a power cut could disable the phone unless backup equipment is in place. Questions worth asking a provider include how emergency calls are handled, what happens during an internet outage, and whether existing extensions or alarm systems are supported on the new setup.
Comparing providers helps businesses understand typical costs and features before committing to a new system.
| Provider Name | Services Offered | Key Features/Benefits |
|---|---|---|
| BT Business | Digital landline, hosted VoIP | UK-wide coverage, number porting support |
| Virgin Media Business | Hosted VoIP, broadband bundles | Combined internet and phone packages |
| Gamma | Cloud phone systems, SIP trunking | Scalable for multi-site businesses |
| 8x8 | Cloud-based business phone systems | Global calling plans, app integration |
| Vonage Business | VoIP and unified communications | Flexible mobile and desktop apps |
Prices, rates, or cost estimates mentioned in this article are based on the latest available information but may change over time. Independent research is advised before making financial decisions.
Typical pricing for business phone systems in the UK ranges from around £10 to £30 per user per month for cloud-based or hosted VoIP services, depending on call packages and included features. Digital landline replacements for a single line often start lower, while larger multi-site cloud systems with advanced call handling can cost more. These figures serve as a general guide rather than a fixed quote, since actual pricing depends on contract length, call volumes and additional hardware requirements.
The shift away from the copper network is a significant but manageable change for UK businesses. By identifying which devices still depend on an old line, confirming the type of service currently in place, and comparing suitable replacement systems, businesses can migrate well ahead of the 2027 deadline without unexpected disruption to calls, payments or safety equipment.
