Replace Landlines with VoIP: UK Migration Guide 2026

Last updated: April 2026

If you still have traditional landlines in your business, you are running out of time. The UK's Public Switched Telephone Network (PSTN) is being permanently shut down in January 2027. After that date, every analogue phone line in the country stops working. No extensions, no exceptions.

This is not a rumour or a maybe. BT Openreach confirmed the shutdown years ago, and the process is already well underway. Thousands of telephone exchanges across the UK have already been switched off. If your area has not been affected yet, it will be soon.

The good news is that replacing your landlines with VoIP is straightforward, usually cheaper than what you are paying now, and gives you a far better phone system in the process. We have helped over 2,000 UK businesses through this exact transition since 2008, and the vast majority wish they had done it sooner.

This guide walks you through everything: what is happening, what you need to do, how much it costs, and how to make the switch without losing your phone numbers or disrupting your business.

---

What Is the PSTN Switch-Off and Why Should You Care?

The PSTN is the traditional telephone network that has carried voice calls across the UK since the 1980s. It runs on copper wires maintained by Openreach, and it powers every standard landline in the country. Your 01, 02, and 03 numbers all run on this network.

BT Openreach announced that the entire PSTN would be retired by January 2027. The reason is simple: the network is old, expensive to maintain, and the technology it relies on is no longer manufactured. Replacement parts are increasingly difficult to source. Continuing to run a network built in the 1980s when modern internet based alternatives exist makes no economic or technical sense.

The switch-off is not happening all at once. Openreach has been working through it exchange by exchange since 2023. Some areas have already lost their analogue service. Others will be cut over in the final months of 2026 and early 2027. But by January 2027, every exchange in the UK will have been migrated.

What This Means for Your Business

If your business currently uses traditional landlines, those lines will stop working when your local exchange is switched off. You will not be able to make or receive calls. There is no "legacy" option to keep the old system running.

This affects:

• Standard business phone lines (PSTN and ISDN)
• Analogue alarm systems connected via phone lines
• EPOS/card payment terminals that dial out over phone lines
• Fax machines still using analogue connections
• Door entry systems wired to phone lines
• Lift emergency phones connected to PSTN

If any of these apply to your business, you need a plan. And that plan starts with replacing your voice calls with VoIP.

---

What Is VoIP and How Does It Replace a Landline?

VoIP stands for Voice over Internet Protocol. Instead of your calls travelling over copper wires, they travel as data packets over your internet connection. Same phone number, same ability to make and receive calls, but using your broadband instead of a dedicated phone line.

From the outside, nothing changes. Your customers dial the same number. Your staff pick up the phone the same way. The call quality is the same or better. The difference is all behind the scenes.

With a hosted VoIP system, your phone system lives in the cloud rather than in a box on your wall. Your provider manages everything: the call routing, the voicemail, the auto attendant, the call recording. You just plug in phones or use an app on your computer or mobile.

The practical benefits over a traditional landline are significant:

• Keep your existing phone numbers. They port across to VoIP with no disruption.
• Work from anywhere. Calls route to your mobile app, laptop, or desk phone, wherever you are.
• Add or remove users in minutes. No waiting for an engineer.
• Get features that landlines never had. Call queues, auto attendant, call recording, voicemail to email, CRM integration.
• Pay less. VoIP is almost always cheaper than the equivalent landline setup.

---

Step by Step: How to Replace Your Landlines with VoIP

Switching from landlines to VoIP is not as complicated as it sounds. Here is the process, broken down into clear steps.

Step 1: Audit Your Current Setup

Before you do anything, document what you have. Count your phone lines, list your phone numbers, and identify every device connected to a phone line. This includes the obvious things like desk phones, but also the less obvious: alarm panels, card machines, fax machines, and door entry systems.

For each item, note whether it is making voice calls or using the line for data (like an alarm dialler sending a signal). Voice calls move to VoIP. Data connections may need a different solution, which we will cover later in this guide.

Step 2: Check Your Broadband

VoIP runs over your internet connection, so your broadband needs to be good enough to handle it. Each concurrent call uses roughly 100kbps of bandwidth in each direction. For a small office with 5 staff, that is 500kbps up and 500kbps down at peak, well within the capability of any decent broadband connection.

If your current broadband is slow or unreliable, this is the time to upgrade. We supply Sky SOGEA broadband at 80Mbps download / 20Mbps upload for just £35+VAT per month. That is more than enough for a busy office with 20+ VoIP users running simultaneously, with plenty of headroom for everything else.

SOGEA stands for Single Order Generic Ethernet Access. It is the broadband connection that runs over the same copper/fibre infrastructure but without a phone line attached. Since you will not need a phone line for VoIP, SOGEA is the logical broadband choice going forward.

If you need something faster, leased lines are available for larger offices, but for the vast majority of small and medium businesses, a standard SOGEA or FTTP connection is more than adequate.

Step 3: Choose Your VoIP System

There are broadly three types of VoIP system:

• Hosted VoIP (cloud PBX). Your provider runs everything. You pay per user per month. This is the most popular option for businesses with 1 to 50 staff. Pricing starts from around £6+VAT/user/month for a basic package, £10 to £15 for a standard package with features like call recording and auto attendant, and £18 to £25 for premium packages with advanced call centre features.

• On-premise IP PBX (like 3CX). The phone system software runs on a server in your office or on a cloud server you control. More flexibility, more control, but more responsibility for maintenance. 3CX is the platform we recommend for businesses that want this level of control.

• Microsoft Teams Phone. If your business already uses Microsoft 365, you can add calling capability to Teams. This works well for some businesses, but it is expensive for small teams and the telephony features are limited compared to a dedicated VoIP system. We have a detailed comparison of Teams alternatives if you are considering this route.

For most small and medium businesses replacing straightforward landlines, hosted VoIP is the right answer. It is simple, affordable, and someone else handles all the technical maintenance.

Get a free VoIP quote tailored to your business and we will recommend the right system for your setup.

Step 4: Port Your Phone Numbers

This is the part most businesses worry about, and it is the part that almost always goes smoothly. Number porting is the process of transferring your existing phone numbers from your old provider to your new VoIP provider. Your customers continue calling the same number. Nothing changes from their perspective.

The porting process takes between 5 and 15 working days depending on the type of number and who currently owns it. Your new VoIP provider handles the paperwork. You sign a Letter of Authority (LOA) confirming you want the numbers moved, and the providers coordinate the switch between themselves.

On the day of the port, calls to your old number are redirected to your new VoIP system. There is typically a brief cutover period of a few minutes, but in practice most businesses experience no noticeable interruption.

Important: Do not cancel your old phone lines before the port completes. If you cancel the line, you lose the number. Always let the porting process handle the switchover.

Step 5: Set Up Your Hardware (or Go Softphone)

You have three options for how your staff actually make and receive calls:

• IP desk phones. These look and feel like traditional phones but connect to your network via ethernet. Brands like Yealink, Snom, Fanvil, Grandstream, Cisco, Polycom, Panasonic and Gigaset make excellent business IP phones. Expect to pay £50 to £150 to purchase outright, or £3 to £5 per month to lease.

• Softphone apps. Software that runs on your computer or mobile phone. Most VoIP providers include a softphone app with every user licence at no extra cost. Great for remote workers and businesses that want to avoid buying hardware altogether.

• A mix of both. Desk phones in the office, softphone apps for staff who work from home or travel. This is the most common setup we see.

Step 6: Go Live

Once your numbers have ported and your phones are configured, you are live. Calls come in on your new system from day one. Most VoIP providers offer a parallel running period where both old and new systems work simultaneously, giving you time to test everything before fully committing.

---

Old Landlines vs VoIP: The Full Comparison

Here is how traditional landlines stack up against a modern VoIP system across every metric that matters.

The cost comparison alone makes a compelling case. A business with 10 traditional phone lines paying £20 per line per month plus call charges is spending at least £200 per month before anyone makes a call. The same business on VoIP at £10 per user per month with calls included spends £100 per month, saving £1,200 per year.

---

What About Alarm Systems, EPOS, and Other Analogue Devices?

This is one of the most important and most overlooked aspects of the PSTN switch-off. Your phone lines are probably doing more than carrying voice calls.

Intruder Alarm Systems

Many burglar alarm systems use a phone line to communicate with the monitoring centre. When the alarm triggers, it dials the monitoring station over the PSTN. Once the PSTN switches off, this connection breaks.

The fix depends on your alarm type:

• Newer alarms (manufactured in the last 5 to 8 years) often have built in IP or cellular connectivity. Check with your alarm company whether your panel can be reconfigured to communicate over broadband or 4G/5G instead.
• Older alarms may need a replacement communicator module. These typically cost £100 to £300 fitted, and convert the alarm's analogue output to an IP or cellular signal.
• Very old systems may need replacing entirely. If your alarm is more than 10 years old, this is probably the right time to upgrade to a modern system with built in connectivity.

Contact your alarm monitoring company now. Do not wait until January 2027 and discover your alarm can no longer call for help.

EPOS and Card Payment Terminals

Older card machines that dial out over a phone line need replacing or converting. Most modern payment terminals use 4G or Wi-Fi, and your payment provider should be able to supply a replacement at low or no cost. This has been happening gradually across the industry for years, so if you still have a dial-up terminal, you are overdue for an upgrade regardless.

Fax Machines

If your business still sends faxes (some industries like law and healthcare still do), you have two options. A fax to email service converts incoming and outgoing faxes to email attachments, eliminating the need for a phone line entirely. Alternatively, some VoIP systems support T.38 fax relay, which lets a traditional fax machine work over your VoIP connection. Ask your VoIP provider which option they recommend.

Door Entry and Lift Phones

Door entry systems and lift emergency phones that use phone lines need converting to IP or cellular alternatives. These are safety critical, so get them sorted early. Your building management company or lift maintenance provider can advise on the specific solution for your equipment.

---

How Much Does It Cost to Switch from Landlines to VoIP?

Let us break down the actual costs involved.

One Off Costs

• IP desk phones: £50 to £150 each to buy, or £3 to £5/month to lease. If you choose softphone apps only, this cost is zero.
• Number porting: Usually free with your new VoIP provider. Some charge a small fee of £5 to £10 per number.
• Broadband upgrade (if needed): Installation is often free on a new contract. Monthly cost for Sky SOGEA 80/20 is £35+VAT.
• Network switch or router upgrade: Only needed if your office network is very old. A basic PoE switch for powering desk phones costs £50 to £150.

Monthly Costs

• VoIP per user: From £6+VAT/month for basic, £10 to £15 for standard, £18 to £25 for premium.
• Broadband: £35+VAT/month for Sky SOGEA 80/20 (sufficient for most offices).
• Call charges: Most VoIP plans include UK landline and mobile calls. International calls are extra but typically much cheaper than traditional rates.

What You Stop Paying

• Traditional line rental: £15 to £25 per line per month, gone.
• ISDN rental: £20 to £40 per channel per month, gone.
• Per minute call charges: Most VoIP plans include calls, so these largely disappear.
• Maintenance contracts on old phone systems: No longer needed.

For a typical office with 10 users, the total cost of switching is often recovered within 3 to 6 months through lower monthly bills. After that, you are saving money every single month.

Get a free, no obligation VoIP quote and see exactly what the switch would cost for your business.

---

Common Concerns and Myths About Replacing Landlines

We have been doing this for 18 years. Here are the concerns we hear most often, and the reality behind each one.

"VoIP call quality is poor"

This was true 15 years ago. Modern VoIP on a decent broadband connection sounds identical to, or better than, a traditional landline. HD Voice codecs deliver clearer audio than analogue lines ever could. If your broadband is reliable, your call quality will be excellent.

"What happens in a power cut?"

Traditional landlines work in power cuts because the phone line carries its own power. VoIP phones need mains electricity and a working internet connection. For most businesses, a power cut means everything stops anyway, no computers, no lights, no heating. Your phones going down too is just part of the same problem.

That said, if phone continuity during power cuts is critical for your business, there are solutions. A small UPS (uninterruptible power supply) can keep your router and phones running for 30 to 60 minutes. And most VoIP systems can automatically divert calls to mobile phones if the office connection goes down, so you never actually miss a call.

"I will lose my phone number"

No. Number porting has been standard practice in UK telecoms for decades. Your existing landline numbers transfer to your VoIP system. Your customers will not notice any change. The process is handled entirely by your providers, you just sign the paperwork.

"It is too complicated to set up"

A good VoIP provider handles the entire setup for you. They configure the system, port your numbers, set up your phones, and test everything before you go live. From your perspective, the old phones get unplugged, the new phones get plugged in, and your numbers ring on the new system. Most migrations for a small office take half a day.

"My internet is not good enough"

It probably is. A standard SOGEA broadband connection at 80/20 can comfortably handle 20+ simultaneous VoIP calls alongside normal internet usage. If you currently have broadband that handles email and web browsing without issues, it will handle VoIP too. If you are in a rural area with genuinely poor broadband, a 4G/5G backup connection can provide resilience.

---

The Cost of Doing Nothing

Some businesses are tempted to wait, to squeeze every last month out of their existing phone lines before being forced to switch. This is a mistake for several reasons.

First, demand for VoIP installations and number ports is increasing rapidly as the January 2027 deadline approaches. Providers are getting busier. Lead times are getting longer. If you wait until late 2026, you may find yourself in a queue.

Second, Openreach is not waiting for January 2027 to start switching off exchanges. Many have already gone. If your exchange is switched off before you have arranged a VoIP replacement, you are left without phones until your new system is ready. That is lost calls, lost business, and lost revenue.

Third, every month you delay is a month of paying more than you need to. Traditional line rental, per minute call charges, and old system maintenance costs add up. Switching sooner means saving sooner.

Compare VoIP options for your business now and avoid the last minute rush.

---

Useful Resources

For more detail on specific aspects of the switch, these guides may help:

• Hosted VoIP for Business UK: Complete Guide covers VoIP features, providers, and costs in depth.
• VoIP Problems and Solutions addresses common technical issues and how to fix them.
• Business VoIP Overview explains our VoIP comparison service and how we help businesses choose the right system.
• Small Business VoIP System UK is tailored specifically for businesses with under 20 staff.

---

Frequently Asked Questions

Can I keep my existing phone number when switching to VoIP?

Yes. Number porting is a standard, regulated process in the UK. Your existing landline numbers (01, 02, 03 prefixes) can all be transferred to your new VoIP provider. The process takes 5 to 15 working days and is handled by your new provider. Your customers will not notice any change.

How long does the whole migration process take?

For a straightforward office with 5 to 20 users, the typical timeline from initial enquiry to going live is 2 to 4 weeks. That includes choosing a system, ordering equipment, porting numbers, and configuring everything. Larger or more complex setups may take longer, but the process is well established and your provider manages the timeline.

Do I need special broadband for VoIP?

You need a reliable broadband connection, but it does not need to be anything exotic. Standard SOGEA or FTTP broadband is fine. We supply Sky SOGEA 80/20 at £35+VAT per month, which comfortably supports 20+ VoIP users. The key requirement is consistency rather than raw speed. A stable 20Mbps connection is better for VoIP than an unstable 100Mbps one.

What happens to my fax machine?

You have two main options. A fax to email service lets you send and receive faxes as email attachments, which is the simplest solution and eliminates the need for a physical machine. Alternatively, some VoIP systems support T.38 fax relay, allowing your existing fax machine to work over the VoIP connection. Most businesses take the opportunity to go paperless and choose the email option.

Is VoIP reliable enough for a business?

Yes. Modern hosted VoIP platforms run across multiple redundant data centres with 99.9%+ uptime guarantees. The main variable is your broadband connection. With a reliable internet connection (and ideally a 4G backup for added resilience), VoIP is as dependable as a traditional phone line. Thousands of UK businesses already rely on it as their sole phone system.

What if I have devices on my phone line that are not phones?

Alarm systems, card machines, fax machines, door entry systems, and lift phones all need individual attention. Each has a specific solution, whether that is an IP/cellular communicator for alarms, a Wi-Fi or 4G card terminal, fax to email, or an IP door entry panel. Your VoIP provider and your individual equipment suppliers can advise on the right solution for each device. The key is to audit everything connected to your phone lines before you start the migration.