Compare Business Phone Lines UK 2026: VoIP, Landline & Virtual Numbers

Choosing a business phone line in 2026 means deciding between three fundamentally different technologies: traditional landline, VoIP (internet-based) and virtual numbers. Each has different costs, features and suitability depending on your business size and needs.

This comparison guide lays out every option side by side with real UK pricing, so you can make an informed decision without needing to call ten different providers.

The Three Types of Business Phone Line

1. Traditional Landline

A physical copper or fibre line connecting your premises to the BT exchange. This has been the standard for decades, but BT is switching off the PSTN network in 2027, making traditional landlines a short-term option at best.

2. VoIP (Voice over Internet Protocol)

Calls travel over your internet connection instead of a dedicated phone line. This is now the standard for UK businesses — cheaper, more flexible, and packed with features that landlines simply cannot offer.

3. Virtual Phone Number

A phone number that isn’t tied to any physical line or location. Calls to the number are forwarded to your mobile, landline, or VoIP system. Ideal for sole traders, startups and businesses that don’t need a full phone system.

Side-by-Side Comparison

Provider Comparison: Who Offers What?

Which Phone Line Type Is Right for Your Business?

You’re a sole trader or freelancer

Start with a virtual number. It costs £3-10/month, gives you a professional 01/02 number separate from your personal mobile, and requires zero hardware. Upgrade to VoIP when you hire your first employee.

You have 2-20 employees

VoIP is the clear winner. The per-user model means you only pay for what you use, and features like auto-attendant and call recording give you enterprise-level professionalism without enterprise-level costs. Start at £6/user/month.

You have 20+ employees

VoIP with a full cloud phone system. At this scale you need call analytics, department routing, ring groups, and integration with your CRM and helpdesk. Look for providers offering dedicated account management and SLA-backed uptime.

You have an existing PBX you want to keep

SIP trunking. This connects your existing phone system to the internet, replacing expensive ISDN lines with cheaper internet-based channels. From £3/channel/month.

How to Switch Business Phone Lines

1. Audit your current setup: How many lines do you have? What numbers? What’s your current monthly spend?
2. Get comparison quotes: Contact at least 3 providers, or use a broker like Connection Technologies to compare them all at once.
3. Port your numbers: Your new provider handles this. Porting takes 1-10 working days.
4. Install and configure: VoIP is live within 24 hours. Configure auto-attendant, voicemail, and call routing through the web portal.
5. Cancel old service: Only cancel your old landline AFTER the port is complete and confirmed working.

Cost Comparison by Business Size

1-Person Business

5-Person Business

20-Person Business

The 2027 PSTN Switch-Off: What It Means for Your Phone Line

BT is turning off the traditional copper phone network in January 2027. This affects every business currently using an analogue phone line, ISDN2, or ISDN30. After the switch-off, these services simply stop working.

If you’re still on a traditional landline, you need to plan your migration now. The options are:

• Switch to VoIP: The most popular choice. Full feature set, lowest ongoing cost.
• Use BT’s Digital Voice: BT’s own VoIP replacement. Simple but limited in features.
• Move to a cloud phone system: The premium option for businesses wanting the full communications platform.

Read our complete guide to preparing for the PSTN switch-off.

Number Types Explained

Geographic Numbers (01/02)

Local area code numbers that give your business a local presence. Available on VoIP, landline and virtual platforms. Customers calling from the same area pay local rates (or free from mobiles).

Non-Geographic Numbers (03)

National rate numbers that cost the same as calling an 01/02 number. Professional and not tied to a location. Popular with businesses operating nationally.

Freephone Numbers (0800/0808)

Free for the caller, you pay per minute received (typically 3-7p/min). Used by larger businesses to encourage inbound calls from potential customers.

International Numbers

VoIP providers can issue you international numbers in specific countries, making it cheap for overseas customers to call you on what appears to be a local number in their country.

Security Considerations

VoIP Security

Modern VoIP systems use TLS (Transport Layer Security) to encrypt the signalling and SRTP (Secure Real-time Transport Protocol) to encrypt the voice data. This is significantly more secure than traditional landlines, which transmit calls as unencrypted analogue signals.

Toll Fraud Protection

VoIP systems can be targeted by hackers who make international calls at your expense. Reputable providers include toll fraud detection (alerting you to unusual call patterns) and international call barring by default.

GDPR Compliance

If you record calls, you must comply with GDPR. This means informing callers that their call is being recorded, storing recordings securely, and deleting them after the retention period. Most hosted VoIP providers handle this automatically — see our call recording compliance guide.

Multi-Line vs Multi-Extension: Understanding the Difference

A common source of confusion when comparing business phone lines is the difference between lines and extensions:

• A phone line is a concurrent call path. If you have 3 phone lines, 3 people can be on external calls simultaneously. A 4th caller gets an engaged tone or goes to voicemail.
• An extension is an internal number assigned to a person or department. You can have 50 extensions but only 10 phone lines — meaning a maximum of 10 simultaneous external calls.

With VoIP, this distinction matters less because each user licence typically includes their own line. A 20-user VoIP system supports 20 concurrent calls by default. With traditional systems, you’d need to buy 20 separate lines.

Call Quality Comparison in Real-World Conditions

We tested call quality across different phone line types in typical UK business conditions:

The takeaway: VoIP on fibre broadband delivers the best call quality in every scenario except power outages, which are easily mitigated with a £100 UPS (uninterruptible power supply) or 4G failover router.

Porting Your Business Number: What Happens Step by Step

Number porting is the process of moving your existing phone number to a new provider. It’s regulated by Ofcom, so your old provider cannot refuse or delay it beyond the standard timescale. Here’s exactly what happens:

1. You provide your details: Your new provider needs your existing phone number(s), account number with the current provider, and a signed Letter of Authority (LOA).
2. New provider submits the port: They contact your old provider through the industry porting system. This triggers a validation check.
3. Old provider confirms: Within 2 working days, your old provider either accepts or rejects the port (rejection only for valid reasons like incorrect account details).
4. Port date is set: Typically 5-10 working days from acceptance. You’ll be told the exact date and time.
5. Switchover: At the agreed time, your number starts routing to the new provider. The changeover typically takes 2-30 minutes.
6. Done: Your old line is automatically cancelled. Check your old provider hasn’t continued billing you.

During the porting process, your phone service continues uninterrupted on the old provider until the moment of switchover.

Business Phone Line Regulations and Compliance

Ofcom Protections

UK business phone customers are protected by Ofcom regulations covering fair contract terms, transparent pricing, and the right to switch providers. Providers must give you a minimum of 30 days’ notice of any price increases and allow you to exit your contract penalty-free if they raise prices beyond the agreed terms.

Data Protection (GDPR)

If your phone system records calls, stores voicemails, or logs caller information, you’re processing personal data under GDPR. You need a lawful basis for processing (legitimate business interest or consent), must inform callers that data is being collected, and must securely store and eventually delete the data.

Emergency Calling (999)

All UK phone services, including VoIP, must support 999 emergency calls. VoIP providers are required to register your business address so that emergency services know your location. If your team works from multiple locations, ensure each location’s address is registered.

Frequently Asked Questions

Can I have a local number even if I’m based elsewhere?

Yes. VoIP and virtual numbers let you choose any UK area code. A London-based business can have a Manchester 0161 number, or vice versa. Many businesses choose multiple local numbers to appear local in different regions.

Are VoIP calls free?

Most VoIP plans include unlimited UK landline and mobile calls in the monthly price. International calls are charged per minute but at rates 50-80% cheaper than traditional phone lines.

What if my internet goes down?

Hosted VoIP providers automatically redirect calls to your mobile or voicemail during outages. You won’t miss a call. For businesses where uptime is critical, a 4G failover router costs £100-200 and provides an automatic backup connection.

Is VoIP reliable enough for a business?

Yes. Enterprise VoIP providers guarantee 99.99% uptime. The remaining 0.01% is handled by automatic mobile failover. In practice, VoIP is now more reliable than traditional landlines in most UK areas.

Can I keep my existing business number?

Yes. Number porting is a legal right. Your new provider manages the transfer. Typical porting time is 1-10 working days with no interruption to service.

Get a Free Phone Line Comparison

Connection Technologies compares business phone lines from every major UK provider. Tell us your team size and current setup, and we’ll send you a tailored comparison within 24 hours — completely free.

Compare Business Phone Lines Free →

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.

IT StrategyCloudCybersecurityAIDigital Transformation

View Full Profile