Your options when the ‘Big Switch Off’ happens in 2025

Public Switch Telephone Network (PSTN) is the standard telephone network connecting people worldwide. It lets users make calls across its network via traditional ‘landline’ phone numbers and is provided by leading carriers in each country or location.

Believe it or not, this complex system of circuits and copper-wiring is over 100 years old - and from inception, to the first international call in 1927 and beyond, it has served as the world’s primary voice communication service.

Despite its past innovation though, PSTN is limited to a single phone line and is only able to handle one call (inbound or outbound) at a time. And though increased mobile phone ownership means consumers are rarely affected by this, for businesses it can be costly - resulting in loss of income and reputational damage.

Introduced in 1986 to address the constraints of PSTN lines, Integrated Services Digital Network (ISDN) allowed businesses to receive and make multiple calls from a single line. By splitting the traditional single copper line into multiple digital channels, ISDN used the outdated PSTN network to move voice communication into the digital age.

Soon, ISDN became the go-to telephony setup for mid-to-large businesses. Alongside access to several phone lines, it also allowed better call quality - making it easier for businesses to communicate with multiple customers at one time.

Its downside, like PSTN, is reliability on physical components. To host an ISDN line, companies need to run phone a line into their building and terminate it in a comms storage unit containing a bulky physical phone system. 

This complex setup makes it costly for companies to install, run and maintain - while its overall size presents problems when relocating or making additions if the business requires. 

Its biggest drawback though, is an inability to keep up with user needs. With remote working growing popular, ISDN’s limited capabilities mean many businesses are abandoning it in favour of flexible and cost-effective cloud-based VoIP options.

Why are PSTN and ISDN being discontinued in the UK?

Both PSTN and ISDN are considered legacy systems which - due to the rise of the internet and digital technology - no longer reflect the needs of consumers and businesses.

On top of costly running and maintenance of these networks, BT is looking to the demands of users in making their decision:

“...we’ve all seen the dramatic changes in technology over the past few years, especially recently. It’s all around us: smartphones, apps, the cloud, Zoom, Internet of Things, and so on.”

Though the switch off hasn’t happened worldwide yet, the UK is not alone - with other countries like Germany switching soon, while the Netherlands have already completed their conversion to digital lines.

88% of UK businesses still use PSTN lines for essential services, indicating that many rely on it for their broadband and any digital services connected to it. 

As the switch off progresses, businesses will likely be contacted by their carrier to talk them through the alternatives and suitable packages. Businesses who don’t migrate, risk losing their broadband and phone line - so reviewing your options now will ensure your services won’t be negatively affected in the future.

What are the alternative broadband options?

Alternatives to traditional broadband include FTTP broadband (Fibre To The Premises) which involves fibre-optic cables running directly from your local broadband exchange into your location. FTTP is recommended for large companies with a greater number of phones, allowing for greater capacity and speed. 

For smaller companies SoGEA connections (Single Order Generic Ethernet Access) offer a cost effective alternative to FTTP, matching the needs of their business without costing as much as FTTP services.

Your service carrier will likely be in touch to advise you, however it’s important to understand how the ‘Big Switch Off’ may affect you as a consumer.

Though PSTN lines are being shut down, some consumers may want to keep the landline number they’ve held for many years. If you’re looking to do this, some carriers offer cloud-based VoIP options where you can ‘port over’ an existing number to your new system.

Systems like BT’s Digital Voice don’t rely on PSTN lines, instead using your broadband connection to send and receive calls. It changes almost nothing about how consumers use or pay for their home phones, while offering an updated and superior digital replacement.

What will happen to the UK’s broadband connections?

If your existing broadband connection relies on a PSTN line, you may need to upgrade a different service. This will be a gradual process for UK customers, with millions of households currently accessing their broadband through a traditional phone connection. 

As for the copper and fibre-optic cables connecting PSTN lines, they’ll be used to carry the digital signals used by VoIP services -  as consumers move towards a full switch.

Of course, if you’re not comfortable with the switch to VoIP, you can still use your mobile phone as your main point of contact. And with a large portion of UK households using mobile devices, it’s a complication-free option.

With most UK businesses still using PSTN connections and close to 45% unaware of how the switch off will affect them, there is a growing need for awareness. 

Many mid-to-large businesses rely on ISDN connections for their phone and internet needs. And while it may be an option for smaller companies - switching to mobile phones entirely isn’t practical and doesn’t offer the functionality of ISDN phone systems. 

These include essentials like call waiting, monitoring and records, internal transfers and voice to email - all which can be included in a tailored VoIP package.

Similar to consumer access, carriers will gradually alert their business customers. However, as this may take time, it’s worth looking into which VoIP carriers and services match the specific needs of your organisation. 

Also like consumer access, companies will be able to retain phone numbers by ‘porting’ them over. For businesses this is vital - eliminating customer confusion and saving time and money alerting customers of the change.

If your business is looking to make the switch, we can help advise you on the best solution and make the migration as seedless as possible.

Brands like T2K offer services like their MiContact Center solution. This innovative VoIP service allows businesses to leave the limitations of ISDN behind; replacing it with a fully flexible, virtual contact centre.

VoIP (Voice over Internet Protocol) allows you to make calls via a broadband connection rather than a phone line. It does this by turning sound into raw data (data packets), which can be transmitted anywhere via a broadband connection. You can make these calls from any of your devices including SIP desk phones and headsets, alongside your computer or mobile device. 

In the same way an email provider hosts your email account, VoIP systems are typically cloud-based and are fully managed by your carrier of choice.  This approach moves away from inflexible, bulky equipment in a comms cupboard, instead allowing users to rent or buy the software/hardware they require with minimal setup or maintenance.

Getting set up is as simple as any monthly subscription; Choose a suitable package, place the order with your provider, activate your account, make a monthly payment and receive features that benefit you as a consumer or a business.

For consumers this includes:

• Portable, untethered mobile devices
• A less expensive alternative to PSTN
• Easy to setup and use
• No broken signal with HD call quality
• Conference calls with more than one person
• Call screening to see exactly who is calling.

And for businesses:

• Add features and system capacity as your business grows
• Flexible equipment and interface, making remote working simple
• Monitor, manage and route calls easily
• Real time reporting to ensure targets are met
• Simple setup and maintenance, lowering costs in the process
• Can be end-to-end encrypted for use with confidential data.

If you’re a business that relies on PSTN or ISDN for your phone and broadband, now is the time to start planning ahead. Doing so now means minimal disruptions to your services and smooth transition to your digital service in 2025.

What does switching to VoIP involve?

Before switching, it’s a good idea to test your internet connection. This will give you an indication of whether you need to consult your broadband provider before purchasing. This is because with VoIP, the service is only as good as your broadband signal, so if your signal isn’t great, consult your provider. 

Consumers may simply need to use a signal booster, while businesses may require more broadband capacity to allow VoIP to function at its highest capability.

Another step is to make sure your broadband network can handle VoIP. Homeowners using wireless broadband may need to upgrade FTTP or a similar exchange-to-location broadband. This is because wireless broadband is susceptible to dropping out, so having cabling direct from the source ensures better overall call quality. 

For businesses, a switch to VoIP may require you to purchase essentials (laptops, mobiles devices, headsets), however, you’ll have none of the ongoing maintenance that ISDN systems require, due to it being cloud-based. This approach reduces repair costs and means businesses only need to invest in the rental or purchase of required equipment.

To eliminate the complication of using multiple providers, some of the leading broadband carriers also offer VoIP services for business too. BT accommodates larger businesses with its Cloud Work VoIP service, while other leading carriers like Sky and Talk Talk offer similar VoIP options.

If your business requires a higher-quality, dedicated VoIP, Gamma Horizon stands out as a powerful yet cost effective solution for businesses looking to future-proof their communication systems. 

On a local level, most small businesses rely on their PSTN line for communications. Aside from the 2025 shutdown itself, there are several drawbacks for SMEs using PSTN lines right now.

Firstly, it limits businesses to one call at a time, so you could miss important, even costly customer calls, while on another call. Having a PSTN line also ties a business and its employees to a single location. This means unless you have your landline forwarded to your mobile device, you may again, miss calls.

If you’re one of a large number of SMEs with zero to one employees, this could result in losing important business needed to keep you afloat. Luckily, over 99% of UK business sits in the SME sector, leading to carriers offering tailored VoIP packages for them too.

How can small businesses benefit from VoIP services?

Although many small business owners may be comfortable with their current communication system, the importance of future proofing your operations can’t be overstated. 

With the majority of technology moving to digital, not doing the same could leave a large section of your customers unable to reach you. For SMEs, moving to a VoIP service might even elevate their business. 

For owners worrying about the maintenance and set up of systems like these, it couldn’t be easier. Systems such as Phoneline+ work from your or any broadband connection, meaning in most cases, you won’t need an engineer to install it - you’ll simply receive your equipment and it’s ready to use.

VoIP can be used in tandem with any mobile device too. This allows you the flexibility to leave your premises and not miss an important call from a colleague or customer. For businesses in remote locations, even if your phone signal is poor, as long as you have a broadband connection available, your service is accessible.

VoIP also allows for a cost-effective approach to business comms. You pay a monthly fee to your carrier in exchange for the features and benefits your business requires. Calling between phones, whether video or voice, is generally free and even landline calling is less expensive than traditional phone lines.

You’ll also be able to scale your system as your business grows - whether that means additional phones or adding relevant features such as call analytics and reporting.

As daunting as the ‘Big Switch Off’ sounds, consumers and businesses still have time to think about how they plan to adapt. If your carrier hasn’t altered you of the change already, get in touch with them to find out more about what they offer.

If you’re a consumer looking to purchase a VoIP service, think about how you plan to use it. Some will be comfortable using mobile devices going forward, where others may wish to keep a landline of sorts.

For businesses, options depend on the size of your organisation. Very small businesses may benefit from consumer-grade VoIP options, where mid-to-large companies requiring CRM-style features, should investigate business phone packages offered by leading or specialist carriers like T2K.

Whether you're a small startup working from home or a corporate enterprise looking for a fully featured system with all the bolt-ons. We have a system suited to you. Contact T2K today to find out more.