What is the PSTN Switch Off and what does it mean for my small business?

All UK landlines will be turned off at the start of 2027. Find out what the Big Switch Off means for SMEs and how you should prepare in 2024.

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Helena Young

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Openreach by BT has announced a one-year delay to the planned Public Switched Telephone Network (PSTN) switch off, over concerns it could impact vulnerable people in the UK.  The company had planned to switch over the outdated, analogue to a faster, Voice over Internet Protocol (VoIP) services by December 2025.

The switchover has instead been delayed until the end of January 2027, at which time any business or home phone call will move to be hosted over IP. Named the ‘Big Switch Off’, the move has big implications for any firm using broadband in its operations. In today’s world, that’s pretty much everyone.

Despite the pause, experts have warned that businesses should still prepare for the change as soon as possible. The later you postpone the shift, the more complicated and costly the process will become. This guide will outline what the change means for small businesses, what the risks and opportunities are, and how to get ready.

PSTN Switch Off dates (updated May 2024)

  • Since September 2023, any broadband or phone services that use the old copper network are no longer sold
  • December 2025 – date the PSTN was due to be switched off
  • January 31 2027 – new date that all home or phone calls will be made via a VoIP-based system
PSTN Switch Off: why has it been delayed?

BT previously announced in December 2023 it would temporarily pause all non-voluntary, managed migrations to the new IP network due to concerns that consumer telecare devices, used by 1.8m eldery and vulnerable people, will not be triggered if the internet goes down.

In May 2024, it officially postponed its plans until the end of January 2027, following significant criticism from campaigns group for elderly people. Many UK business owners also reported being underprepared for the switch over.

What is the PSTN Switch Off?

The Public Switched Telephone Network (PSTN) is the traditional telephone network that was first established in 1875. 150 years later, BT Openreach has decided the equipment is too old to stay in use. The company has already begun to upgrade the old copper wires that currently make up the PSTN.

Over the next three years, Openreach will swap these wires out for fibre-optic cables as part of the so-called Big PSTN Switch Off. As a result, every home and business in the UK will be moved onto a digital network from 2027.

The process is already underway. In September 2023, telephone providers including Virgin Media officially stopped selling hardware models that use the copper network. You will now need to purchase a modern communication system hosted via VoIP.

What is the ISDN Switch Off?

The ISDN was introduced to the PSTN in 1986 by BT to transmit data that the PSTN couldn’t facilitate previously, like video calls.

However, the ISDN is now outdated and only available in older teleconferencing systems and similar legacy systems. Like the PSTN, the ISDN will be shut down in January 2027 in favor of modern technologies like VoIP.

I rely on a landline - can I still use it?

Current equipment will continue to work for at least another two years, but, if your business communications are currently hosted using landlines, there will not be an option for businesses to continue on the PSTN or ISDN after January 2027.

Already, as of September 2023, Openreach will not let suppliers order any new broadband or phone services that rely on the old copper network. With the clock ticking, 2024 is the best time to begin the switch over.

Why are landlines being switched to VoIP?

VoIP telephone systems are hosted over the internet. Specifically, they use fibre optic instead of the PSTN’s copper cables. These ensure a stronger internet connection, meaning VoIP telephone systems are better for hosting higher-quality calls compared to both the PSTN and ISDN. This gives users:

  • Better connectivity: faster broadband will improve your team’s productivity and overall output, having a positive impact on profitability
  • Improved customer relationships: having a faster, more stable telephone infrastructure means a better experience for product or service users
  • Flexible packages: because most VoIP packages work on a per-user pricing model, SMEs can save money by prioritising the connections they require
  • Cheaper deals: VoIP prices will become more competitive over time as Openreach incentivises suppliers to migrate more customers onto these future-proofed products
  • Supports remote working: Kristian Torode explains that by using VoIP number porting, “…any device can connect to the system on one phone number to support flexible working.”

Tom Grange is the head of connectivity at Bionic, a business broadband provider. Grange explains, “The service is quicker and more adaptable than copper and ISDN lines. Calls can be made from smartphones and laptops from wherever you are, with high-quality sound.”

PSTN Switch Off: how will I be affected?

Don’t feel confused if you’ve only just heard about the Big Switch Off. Last year, a Which? survey found that 74% of consumers with a copper landline connection are unaware of the migration.

Telecoms providers will take care of much of the migration admin, by contacting customers at least four weeks ahead of any switching over taking place in their region.

However, if you’re looking for a better broadband deal, savvy business owners are advised to use this time to purchase or upgrade to a small business VoIP system that’s better value-for-money.

How will I be affected?

Once the PSTN has been turned off, businesses will lose all service if they are still using legacy products connected to ISDN, such as:

  • Alarm systems
  • ATM machines
  • Franking machines
  • Fax machines
  • Printers
  • Dial-up POS (card machines)
  • Video conferencing 
  • Live streaming
  • File downloading

VoIP can only be used to host phone or video calls. Card machines and other hardware cannot be hosted using VoIP software. If your machines still connect to a physical telephone line, we recommend finding a unit that uses WiFi.

I’m based offline – will I be affected?

Any business that currently uses ISDN in its operations will be affected by the PSTN Big Switch Off, which is why it’s important that every firm starts preparing for the change by upgrading their business telephone system.

Sara Sheikh is the head of product management at Gamma, a telecommunications provider. Sheikh predicts that the PSTN Switch Off “will have far-reaching implications for every industry” including brick-and-mortar businesses.

“Retail, hospitality, and other customer-facing businesses will need to update their systems to ensure that they can still provide quality customer service,” she clarifies.

PSTN Switch Off: when do I need to switch?

Although the official switch off won’t happen until the start of 2027, switching to a modern, VoIP-based telephone provider should be done as soon as possible. That’s because not switching soon enough brings risks to businesses.

Kristian Torode is the director and cofounder of the business telecoms provider, Crystaline. “There could be some interruptions to services as businesses scramble to upgrade,” he cautions. “There are over 25 million connections to be switched over by the deadline. Making the switch sooner rather than later will be essential.”

The risks for businesses of not switching to a VoIP system in time include:

  • Choosing the wrong supplier: give yourself time to research the best business telephone providers and save money in the long-term
  • Increased costs: get a deal early supplier scaremongering could see VoIP prices getting pushed up closer to the deadline
  • Missing out on fast broadband: with some locations already offering fibre-optic internet, you could already be missing out on the benefits

How do I switch to VoIP?

In our expert guide on how to prepare for the PSTN Switch Off, we outline the five steps to install VoIP. To start, companies should design a detailed migration plan as soon as possible to ensure they are considering budget, required features, infrastructure needs, and employee training.

The next step is to partner with the right provider. Research the top VoIP providers to ensure you are fully aware of each company’s strengths and weaknesses. Seek recommendations from fellow business owners and read reviews to make an informed decision.

If you want to stick with your current provider, start a conversation with their customer service team now about the options available. Should you need to buy new equipment, like a new router, your provider should automatically arrange this.

>> Read our guide to installing a VoIP telephone system to prepare for the Big Switch Off.

What should I look for in a VoIP phone system?

Duncan Shaw, the director at Connectus, a tech firm, recommends that SMEs don’t see the switch-off as a straightforward process of replacing what they have today. “Consider how you want to make communications work for you to maximise your ability to reach customers.”

1. Connectivity: perhaps the most important aspect of a telephone provider is the strength of their connection. Be sure to carry out thorough research into every brand’s broadband speed. That way, you can have confident in a reliable connection that will keep you closely connected with customers.

2. Flexibility: if you have a hybrid workforce, it makes sense to purchase business mobile phones rather than upgrade to a brand-new telephone system. “It’s vital to take informed decisions, remove risk, and minimise the complexity from the process,” says Shaw. “This, in turn, will help you to control costs.”

3. Number porting: this is the process of moving a telephone number from one communications provider (CP) to another. It can take weeks, depending on the system you use, so it’s a good idea to ask your provider how long the change will take to mitigate any business disruption.

Learn more: top five features every office phone system should have 📞

PSTN Switch Off: next steps

Migrating existing business technology is stressful. But it’s important that SMEs recognise the huge opportunities that the Big Switch Off presents not just the challenges.

Transitioning to a VoIP subscription as soon as possible will give business owners access to a much cheaper and more powerful call infrastructure. IP systems give firms access to high-quality lines, which can boost productivity and help ensure a seamless customer experience.

Start by comparing quotes with our simple cost comparison webform to find the best provider for your budget. It’s entirely free and will recommend the most suitable VoIP system for you based on your unique user needs and feature requirements.

Related reading:

PSTN Switch Off FAQs
  • Apart from IP, are there other PSTN alternatives?
    No. All telecommunication will be conducted through the internet, which means businesses must move to an IP form to prepare for the Big Switch Off, like VoIP.
  • How do I know if my provider will switch me to another plan?
    Your provider will contact you to tell you when the service is moving and help you switch. If you want to move to a VoIP service now, you can do so by upgrading to a new phone and broadband package.
  • How much will the PSTN switch off cost me?
    In the long-term, you should save money as a result of switching. IP is typically cheaper to run than the old copper network as it uses the internet, not expensive infrastructure.
  • How would I make a call if there was a power cut?
    Providers are prepared for this. Once the Big Switch Off has occurred, back-up batteries will ensure that calls can be placed in the event of an emergency.
  • Is VoIP more reliable than PSTN?
    Yes. Once landlines have been phased out, VoIP will run with fibre optic and be more reliable than PSTN. Currently, PSTN uses old copper wiring to relay data, which is subject to damage and more likely to experience poor connectivity.
  • Can I keep my current landline number with the PSTN switch off?
    Yes. Unless you change broadband providers, you will be able to keep the same business phone number, so there shouldn’t be any disruptions to your operations.
  • Do I need to buy a new phone after the PSTN switch off?
    No, your broadband provider should send you any new equipment needed to transition to VoIP. This includes all telephone handsets and a new router, if relevant.

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Written by:
Helena Young
Helena is Lead Writer at Startups. As resident people and premises expert, she's an authority on topics such as business energy, office and coworking spaces, and project management software. With a background in PR and marketing, Helena also manages the Startups 100 Index and is passionate about giving early-stage startups a platform to boost their brands. From interviewing Wetherspoon's boss Tim Martin to spotting data-led working from home trends, her insight has been featured by major trade publications including the ICAEW, and news outlets like the BBC, ITV News, Daily Express, and HuffPost UK.

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