Cheap Business Phone Line UK 2026: Cut Costs Without Cutting Quality

By Andy Pickett · Managing Director

Published 10 March 2026 · Updated 28 March 2026 · About the author

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Last updated: July 2025  |  Reviewed by: Connection Technologies business telecoms team  |  Pricing verified: All provider pricing checked and updated July 2025

The 3 Cheapest Business Phone Line Options in the UK (2025)

Before we dive into the full comparison, here’s a quick look at the three cheapest ways to get a business phone line in the UK right now. All pricing is verified as of July 2025.

Traditional Business Phone Lines vs VoIP: 2025 Price Comparison

If you’re still paying for a traditional BT-style business phone line, you’re almost certainly spending more than you need to. Here’s how the costs stack up in 2025:

That’s a potential saving of over £1,800 per year for a business with just five phone lines — and the VoIP option actually includes more features, not fewer.

Option 1: VoIP Hosted Phone Line — From £5/Month Per User

A VoIP (Voice over Internet Protocol) hosted phone line is the most popular — and best value — cheap business phone line option for UK businesses in 2025. It’s a complete cloud-based phone system where your provider manages the technology and you simply make and receive calls over your internet connection.

What you get for £5/month

• Unlimited UK landline and mobile calls — no per-minute charges
• A professional business phone number — local, national or 0800
• Call routing and auto-attendant — “Press 1 for sales, press 2 for support”
• Voicemail-to-email — messages delivered straight to your inbox
• Mobile and desktop apps — take your business line with you anywhere
• AI call handling — automated call summaries and intelligent routing
• CRM integration — connect with popular business tools
• Multi-device support — desk phone, mobile, laptop and tablet
• Online management portal — manage settings, users and call data yourself

Who it’s best for

VoIP hosted telephony is ideal for small and medium-sized businesses, remote teams, multi-site companies and anyone looking to replace an ageing traditional phone system with something modern, flexible and significantly cheaper. If you have 2–200+ users and want a fully managed phone system without the complexity, this is your best option.

Why it’s so cheap

Because there’s no physical phone line to maintain. VoIP runs over your existing broadband, so providers don’t have the infrastructure costs that Openreach and BT pass on to you. That saving gets passed directly to your monthly bill.

Option 2: SIP Trunking — From £3.50/Month Per Channel

SIP trunking is the cheapest way to get business phone lines if you already have a PBX (Private Branch Exchange) phone system on your premises. Instead of paying for expensive ISDN lines from Openreach, SIP trunks deliver your calls over broadband at a fraction of the price.

What you get for £3.50/month per channel

• One concurrent call channel — each SIP trunk handles one simultaneous call
• Pay-as-you-go or bundled minutes — flexible call charging options
• Number porting — keep all your existing business numbers
• Instant scalability — add or remove channels in minutes, not weeks
• ISDN replacement — essential before the 2027 PSTN switch-off
• Resilience and failover — automatic rerouting if your primary connection fails

Who it’s best for

SIP trunking is best for businesses that have invested in an on-premise PBX system (such as Avaya, Mitel, Panasonic or similar) and want to keep using it whilst dramatically reducing their line rental costs. It’s also the go-to solution for larger businesses with high call volumes that need many concurrent call channels.

Typical savings

An ISDN2 line (2 channels) from Openreach currently costs around £28–£35/month. Two SIP trunk channels cost from just £7/month — a saving of up to 80%. For businesses with ISDN30 connections (used for 8–30 channels), the savings are even more dramatic — often thousands of pounds per year.

Option 3: Virtual Business Phone Number — From £1.50/Month

If you’re a sole trader, freelancer or micro-business and just need a professional business phone number without the complexity of a full phone system, a virtual phone number is the cheapest option of all.

What you get for £1.50/month

• A professional business number — choose a local geographic number (e.g., 0161 for Manchester, 0207 for London), a national 03 number, or an 0800 freephone number
• Call forwarding — all calls routed to your existing mobile or home phone
• Voicemail-to-email — never miss a message
• No hardware required — use your current mobile phone
• Instant setup — live the same day you order

Who it’s best for

Virtual numbers are perfect for sole traders who want to separate their business and personal calls, freelancers who want a local presence in a specific area, and startups that need a professional image before they’re ready to invest in a full phone system.

Limitations to be aware of

A virtual number is not a full phone system. You won’t get features like multi-user call routing, CRM integration or AI call handling. If you need those, VoIP hosted telephony (from £5/month) is the better option. But if all you need is a professional number that rings your mobile — a virtual number is unbeatable value.

⚠️ The PSTN Switch-Off: Why You Must Act Before January 2027

If you’re still using a traditional analogue phone line or ISDN, this section is critical. The UK’s Public Switched Telephone Network (PSTN) — the copper-wire infrastructure that’s carried phone calls since the 1800s — is being permanently switched off in January 2027.

What this means for your business

• Openreach has already stopped selling new PSTN and ISDN lines at the vast majority of UK exchanges
• Existing PSTN/ISDN lines will stop working when the switch-off completes in January 2027
• You cannot delay — if you wait until the last minute, providers will be overwhelmed with migration requests and you risk downtime
• Number porting takes time — typically 5–10 working days, so last-minute switches are risky

The silver lining

Being forced to switch is actually good news for your budget. Moving from a traditional phone line to VoIP means you’ll pay less, get more features and have a phone system that’s future-proof. Think of the PSTN switch-off not as a problem, but as the push you need to finally stop overpaying.

How to Choose the Cheapest Business Phone Line for Your Needs

The right option depends on your business size, current setup and what features you need. Here’s a quick decision guide:

Choose a VoIP hosted phone line (from £5/month) if you:

• Have 2 or more staff who need phone access
• Want a complete, fully managed phone system
• Need features like call routing, voicemail-to-email and a mobile app
• Are replacing an old traditional phone system
• Have remote or hybrid workers

Choose SIP trunking (from £3.50/month per channel) if you:

• Already have a PBX phone system you want to keep
• Need to replace ISDN lines before the 2027 switch-off
• Have high call volumes and need many concurrent channels
• Want the cheapest possible per-channel cost

Choose a virtual number (from £1.50/month) if you:

• Are a sole trader or one-person business
• Just need a professional number that rings your mobile
• Want a local presence in a specific area without an office there
• Don’t need advanced call features right now

Hidden Costs to Watch Out for With Cheap Business Phone Lines

Not all “cheap” phone line providers are genuinely cheap once you factor in the extras. Here are the most common hidden costs to look out for:

1. Setup and activation fees

Some providers charge £20–£50+ per line to set up your service. Connection Technologies doesn’t charge setup fees on standard plans.

2. Per-minute call charges on top of line rental

A line that looks cheap at £4/month can become expensive if every call is charged at 10p–20p per minute. Always check whether UK calls are included or charged separately. Our VoIP plans include unlimited UK calls in the monthly price.

3. Feature add-on charges

Watch out for providers who advertise a low base price then charge extra for essentials like:

• Call recording — often £3–£8/month extra elsewhere
• Voicemail-to-email — sometimes £2–£5/month extra
• Auto-attendant / IVR menus — £5–£15/month extra with some providers
• Call analytics and reporting — often only available on “premium” tiers

With Connection Technologies, all of these features are included in our standard plans from £5/month.

4. Long contract lock-ins

Some budget providers lock you into 24 or 36-month contracts with hefty early termination fees. We offer 30-day rolling contracts so you’re never trapped.

5. Number porting fees

Moving your existing business number should be free or very low cost. Some providers charge £10–£25 per number. We handle number porting at no extra charge.

What You Need to Set Up a Cheap Business Phone Line

One of the best things about modern VoIP phone lines is how little you need to get started:

Essential requirements

• A broadband connection — minimum 1 Mbps upload speed per concurrent call (most UK broadband connections easily handle this)
• A device to make calls on — this can be your existing smartphone, laptop, tablet or desktop PC using a free softphone app

Optional (but recommended)

• An IP desk phone — if you prefer a traditional handset experience, quality IP phones are available from around £40–£80. We can supply preconfigured handsets ready to plug in
• A headset — for comfort during longer calls, especially if using a softphone on a computer
• A dedicated router or QoS settings — for businesses with 10+ concurrent calls, configuring Quality of Service (QoS) on your router prioritises voice traffic for crystal-clear calls

What you definitely don’t need

• ❌ A traditional phone line from Openreach
• ❌ Expensive on-premise PBX hardware (unless you’re choosing SIP trunking)
• ❌ An IT team — everything is managed in the cloud
• ❌ An engineer visit — setup is fully remote

Can You Keep Your Business Phone Number? (Yes)

One of the biggest concerns businesses have when switching to a cheaper phone line is losing their existing number. The good news: you can keep your number.

The process is called number porting and works like this:

1. You provide your current number(s) and account details to your new provider
2. Your new provider submits a porting request to your old provider
3. The port completes in 5–10 working days — your old line stays active until the exact switchover moment
4. Zero downtime — calls seamlessly transfer to your new VoIP system

At Connection Technologies, we manage the entire porting process for you. We’ll configure and test your new system before the port completes, so you’re fully ready on day one.

Real-World Savings: How Much Could You Save?

Here’s what the switch from a traditional phone line to VoIP looks like in practice for different business sizes:

Pricing based on typical UK business telephony costs as of July 2025. Traditional line costs include BT Business line rental and average call charges. VoIP costs based on Connection Technologies plans at £5–£10 per user per month with unlimited UK calls included.

Why Choose Connection Technologies for Your Cheap Business Phone Line?

There are dozens of VoIP providers in the UK. Here’s why businesses choose Connection Technologies:

We’re not the cheapest provider for every scenario — but when you factor in what’s actually included at our price point, we consistently offer the best value for UK businesses. And unlike many budget providers, we don’t disappear after the sale. You get dedicated UK-based support from a team that knows your setup.

How to Switch to a Cheaper Business Phone Line (Step by Step)

Switching is simpler than most businesses expect. Here’s the typical process with Connection Technologies:

1. Get a free quote — fill in our quick form or call us. We’ll review your current setup and recommend the cheapest option
2. We design your system — call routing, auto-attendant menus, user extensions, mobile apps — configured to your exact requirements
3. We set up and test everything — your new system goes live on a new temporary number first so we can test call quality and features
4. We port your existing numbers — your current numbers are transferred to the new system (5–10 working days). Your old line stays active until the port completes
5. You go live — seamless switchover with zero downtime. We monitor the first few days to ensure everything is perfect
6. Ongoing support — we’re here for adds, moves and changes as your business grows

The entire process typically takes 1–3 weeks from start to finish, depending on the complexity of your requirements and the number of ports needed.

Frequently Asked Questions About Cheap Business Phone Lines

What is the cheapest business phone line in the UK in 2025?

The cheapest business phone line in the UK in 2025 is a VoIP (Voice over IP) line, which typically costs between £5 and £10 per user per month. Providers like Connection Technologies offer hosted VoIP plans from £5/month that include unlimited UK calls, call routing, voicemail-to-email, mobile apps and AI-powered call handling. This is significantly cheaper than traditional BT-style landlines, which now cost £30–£46 per month for line rental alone — before any call charges.

Can I keep my existing business phone number if I switch to VoIP?

Yes, you can keep your existing business phone number when switching to VoIP. This process is called number porting and is handled by your new provider. At Connection Technologies, we manage the entire porting process for you, which typically takes 5–10 working days. There is no downtime — your old line remains active until the port completes.

What happens to my business phone line when the PSTN switches off?

The UK’s Public Switched Telephone Network (PSTN) is being permanently retired in January 2027. Openreach has already issued stop-sell orders on new PSTN and ISDN connections at virtually all UK exchanges. If you’re still using a traditional analogue phone line, it will stop working when the switch-off completes. You need to migrate to a VoIP-based or digital phone service before this deadline to avoid losing your business phone line.

Is VoIP reliable enough for business calls?

Yes, modern VoIP is extremely reliable for business use. With a stable broadband connection of at least 1 Mbps per concurrent call, VoIP call quality matches or exceeds traditional landlines thanks to HD voice codecs. Most business VoIP providers also offer built-in failover features such as automatic call forwarding to mobile numbers if your internet connection drops, ensuring you never miss a call.

What is the difference between VoIP, SIP trunking and a virtual phone number?

VoIP (hosted telephony) is a complete cloud-based phone system where the provider manages everything — ideal for businesses replacing their entire phone setup. SIP trunking connects an existing on-premise PBX system to the internet, replacing traditional ISDN lines — best for larger businesses that want to keep their current hardware. A virtual phone number is simply a number that forwards calls to another phone (mobile or landline) without any special equipment — perfect for sole traders and micro-businesses wanting a professional local or 0800 number.

Do I need special equipment for a cheap business phone line?

Not necessarily. VoIP services can run on devices you already own — smartphones, laptops, tablets and desktop PCs — using a softphone app. If you prefer a traditional desk phone experience, IP handsets are available from around £40–£80 per unit. Many VoIP providers, including Connection Technologies, provide preconfigured handsets or allow you to use your existing SIP-compatible phones.

How much can I save by switching from a traditional phone line to VoIP?

Most UK businesses save between 40% and 70% by switching from a traditional PSTN or ISDN phone line to VoIP. A typical BT business line costs £30–£46 per month in rental alone, plus per-minute call charges. A VoIP line with unlimited UK calls starts from just £5–£10 per month. For a small business with five lines, this could mean savings of over £1,800 per year.

How quickly can I set up a new cheap business phone line?

A new VoIP business phone line can be set up within 24–48 hours if you’re taking a new number. If you’re porting an existing number from another provider, the process typically takes 5–10 working days. Connection Technologies handles all provisioning and can have your system configured and tested before your number port completes, ensuring zero disruption.

What is the cheapest way to get a business phone number without a phone system?

The cheapest way to get a professional business phone number without a full phone system is a virtual number. These cost from just £1.50 per month and forward incoming calls to your existing mobile or home phone. You get a local geographic number, an 0800 freephone number, or a national 03 number — giving your business a professional image without any hardware or complex setup.

Are there any hidden costs with cheap VoIP business phone lines?

Reputable VoIP providers like Connection Technologies include all core features in their monthly price with no hidden fees. However, some budget providers charge extra for features like call recording, voicemail-to-email, auto-attendant menus or international calls. Always check what is included in the base price. With Connection Technologies, features such as unlimited UK calls, call routing, voicemail-to-email, mobile apps and an online management portal are all included from £5 per user per month.

For the absolute lowest per-minute call costs, SIP trunking typically beats even the cheapest VoIP plans — from £3/channel/month with no per-minute charges on many plans.

For the cheapest all-in-one option, hosted VoIP bundles your phone line, calls and features into a single per-user cost — often cheaper than a traditional line plus call charges.

Written by

Andy Pickett

CTO and AI Champion

Andrew is a Chief Technology Officer with over 15 years’ experience in IT and telecommunications, leading the design and delivery of robust, scalable technology solutions.

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