Prepare your business for the PSTN switch-off
The UK’s old analogue phone network is being switched off, currently expected by 31 January 2027.


Why use Chrome for the PSTN Switch Off?
That means businesses still using traditional phone lines, ISDN, ADSL or other older line-based services need to move to digital alternatives.
It is not only about desk phones.
Older lines may also support alarms, lifts, door-entry systems, payment devices, fax machines, broadband services and other equipment that is easy to forget about until it stops working.
Chrome can help you review what you have, understand what needs replacing and plan the move to a digital setup that fits your business.
We’ll keep the review practical, clear and focused on what needs to happen next.

What the PSTN switch-off means
PSTN stands for Public Switched Telephone Network.
It is the older analogue network that has carried traditional landline phone calls for decades.
The telecoms industry is retiring this network, sometimes called the landline switch off, digital switchover or big switch off, and moving voice services to digital technology. You may hear this called VoIP, IP telephony, cloud telephony, digital voice or All-IP.
For businesses, the change can affect more than calls.
Services that may need checking include traditional analogue phone lines, ISDN phone systems, ADSL broadband, some older broadband services linked to copper lines, fax machines, alarm lines, lift emergency phones, door-entry systems, payment terminals, CCTV or monitoring equipment using a phone line, and other specialist devices connected to legacy lines.
The ISDN switch off and the wider analogue switch off both cover this ground. Some lines will be obvious. Others may sit quietly in the background.
That is why the first step is a proper review.

Why acting early helps
The deadline may still feel a while away.
The issue is that finding every affected line, checking connected equipment and arranging replacements can take longer than expected.
Some businesses also have several sites, older contracts or lines that nobody has looked at for years.
Leaving it late can make the move harder.
You may need to check what each line supports, speak to alarm or lift providers, plan number porting, upgrade internet connectivity, replace handsets, arrange installation dates and test services after the change.
Chrome can help turn this into a clear plan.
The aim is not to change everything at once. It is to know what needs changing, what can stay and who is responsible for each part.
Find every line
Older contracts and sites nobody has reviewed for years.
Check what is connected
Alarms, lifts, door entry and card machines.
Speak to providers
Alarm and lift companies need notice to make changes.
Plan number porting
Keeping existing numbers takes time to arrange.
One Chrome team for your wider technology
The PSTN switch-off can touch several parts of the working day.
Phones, internet, Wi-Fi, payment devices, alarms, Microsoft 365 and managed IT may all be involved.
Chrome can also help with business phone systems, business internet, 5G and backup connectivity, managed and co-managed IT, Microsoft 365, cyber security, CCTV and access control, and workplace technology.
Bringing agreed services together gives your team one place to start.
We’ll also document where another provider, landlord, alarm company, lift company or equipment supplier remains responsible.
Clear ownership saves a lot of head-scratching later.
Start with the lines and devices you already have
Before replacing anything, it is important to understand what is already in place.
Chrome can help review the phone lines, broadband, numbers and connected services your business uses.
This is especially useful if you have more than one site, older phone systems, alarm or lift lines, payment devices, fax machines, broadband linked to a phone line, or bills with unclear line descriptions.
Please do not cancel a line until you know what it supports.
A line that looks unused on a bill may still be connected to something important. That could be a lift emergency phone, intruder alarm, fire alarm, door-entry system, payment terminal or monitoring device.
Chrome can help identify where older services may be in use. The equipment provider may still need to confirm compatibility, replacement options or testing requirements.
We’ll make clear what Chrome manages and where another provider needs to be involved.
This avoids replacing a line before someone has checked the device attached to it.
Move old phone lines to digital calling
For many businesses, the PSTN switch-off is a chance to move from older phone lines to a cloud phone system.
ChromeX can help your team make and receive calls using an internet connection rather than a traditional phone line.
It can support office phones, mobile apps, desktop calling and useful call features that are harder to manage on older systems, including call routing, voicemail, mobile and desktop apps, call recording where included, and reporting where included.
The right setup depends on your users, sites, devices and call requirements.
We’ll explain what needs replacing, what can be reused and what your team needs to know before the change.
We can also help plan number porting where numbers need to move from older lines to the new service.
The important part is simple: do not cancel the old line before the number and any connected services have been checked.
Check the connection, power and backup plan
Digital phone services need a suitable internet connection.
That does not mean every business needs the largest connection available.
It does mean the connection should suit the number of users, the phone system, cloud tools and the work being done online.
Chrome can review your connectivity alongside the phone system, including business broadband, full fibre or FTTP, a leased line, 5G backup or satellite connectivity where other options are limited.
Digital phone services also rely on equipment at the premises, such as routers, switches, handsets and broadband equipment.
If that equipment loses power, the phone service may not work unless backup arrangements are in place.
For some businesses, staff can use mobiles or work from another location. For others, it needs more thought.
Chrome can discuss practical options such as battery backup, mobile connectivity, call routing to mobiles or another agreed continuity plan.
The right answer depends on how your business uses phones and which services need to remain available.
We’ll explain the options before you move, not after a power cut has already made the point.
Support for several sites
Multi-site businesses can have a mix of old and new services.
One location may already use cloud phones. Another may still have ISDN. A smaller site may have an alarm line that nobody has checked for years.
Chrome can help review each location and build a clear record of what needs attention.
We can support site checks, line reviews, number porting planning, connectivity checks, phone system replacement, backup options, supplier coordination and post-change testing.
This helps avoid a different plan, provider and support route for every address.
It also gives your team a clearer view of what is changing, when it is changing and who needs to be involved.
Five steps from old lines to digital calling
The switch off is easier handled early. This is how we work through it with you.
Review what you have
Identify what may be affected
Recommend the right replacement
Plan the move
Support after the change
A clear plan before the old network goes
The PSTN switch-off is easier to manage when you know what you have and what needs to change.
Read what customers say about Chrome’s communication, support and the people behind the service in our reviews.
What the switch-off means for your lines and equipment
Common questions about the PSTN switch off: which lines are affected, what the deadline means and what needs replacing.
When is the PSTN switch-off?
The UK’s PSTN switch-off is currently expected by 31 January 2027, following an earlier delay from the original December 2025 date. Businesses should review older phone lines, ISDN, ADSL and connected services well before that date, and Chrome will confirm the latest position when we talk.
Will the switch-off only affect phones?
No. It may also affect services connected to older phone lines, such as alarms, lifts, door-entry systems, payment devices, fax machines, monitoring equipment and some broadband services.
What will replace PSTN lines, and can we keep our numbers?
Most businesses will move to digital calling using a cloud phone system, VoIP, SIP trunking or another IP-based service. This is sometimes explained as VoIP vs PSTN when comparing the old and new approaches side by side.
In many cases, business numbers can be moved to a new digital phone service. Number porting should be planned carefully. Do not cancel the old line before the number has been moved.
Do we need better broadband?
Possibly. Digital phone services use an internet connection, so the connection should be reviewed before you move. Chrome can check what is available and whether a backup option should be considered.
What should we do first?
Start by finding out what lines, numbers and connected services you currently have. Chrome can help review your setup, identify services that may be affected and recommend the next step.
Not sure what still uses an old line?
That is exactly why it is worth checking now.
Chrome can review your current phone lines, broadband and connected services before the PSTN switch-off.
You’ll get a clear plan for what needs replacing, what needs testing and who needs to be involved.