As a newly renewed 3CX Bronze Partner, and with over 15 years of experience in VoIP Phone Systems, we answer a range of 3CX-related questions from both existing customers and new enquiries. To make things easier for businesses exploring 3CX for the first time, we've put together answers to the most common questions we've been asked ranging from costs, features, call quality, equipment, security, and much more.

Core Understanding

What is a VoIP phone system, and are there per-minute charges?

VoIP (Voice over Internet Protocol) is a phone system that transmits voice calls over the internet rather than traditional copper phone lines. Businesses still make and receive calls as normal the difference is the underlying network technology.

Whether there are per-minute charges depends on the plan. Many UK providers offer bundled call minutes (for example, 3000 UK landline/1000 mobile calls), while international calls may be billed per minute.

What is a SIP trunk?

A SIP trunk is the virtual equivalent of a physical phone line. It connects your VoIP phone system to the public telephone network so you can make and receive external calls. SIP trunks replace older ISDN circuits and are typically cheaper and more scalable.

What is 3CX?

3CX is a software-based business phone system (PBX) that runs on Windows or Linux in the cloud. It delivers all the aspects you would expect from a traditional phone system, like call handling, video, chat, call queues, softphones, mobile apps, and contact centre functionality under one platform. It's widely used due to its flexibility, reliability, reporting and cost-efficiency.

Suitability & Benefits

Do VoIP phone systems work for small businesses?

Yes in fact, small businesses often benefit the most. VoIP removes the upfront costs of legacy telecoms and makes it easier to handle calls professionally, even with remote or distributed teams.

Are VoIP phone systems affordable?

Compared to ISDN or on-premise PBX hardware, VoIP is significantly more cost-effective. You avoid the capital expense of physical lines, maintenance contracts, and replacement hardware or hardware entirely with the ability to use 3CX on mobile and/or computers with a headset. Call costs and international rates can be lower too with SIP trunk packages.

What are VoIP phone system best practices for UK businesses?

Key best practices include:

• Use business-grade broadband (ideally with QoS)

• Ensure a proper router/firewall configuration

• Choose a reputable SIP provider

• Implement security policies (passwords, TLS/SRTP, etc.)

• Train staff on softphone/mobile usage

• Work with an MSP for ongoing support

• These ensure performance, uptime, and call quality.

Features & Functionality

Does it come with voicemail-to-email or transcription?

Yes. Voicemail-to-email is standard on platforms like 3CX. Voicemail transcription depends on the configuration and language support, and is increasingly available through cloud add-ons.

Will calls be secure/encrypted?

Modern VoIP supports TLS encryption for signalling and SRTP (Secure Real-time Transport Protocol) for media streams, protecting call data from interception. Security also depends on firewall configuration and SIP provider quality — areas where an MSP like Network Ltd typically assists.

Practical Questions

Will the call quality be as good as a landline?

With a suitable internet connection and QoS, VoIP often delivers higher audio quality than legacy landlines through HD voice codecs.

What happens if the internet goes down?

VoIP systems can be designed with failover options such as:

• forwarding to mobile numbers

• 4G/5G backup internet

• hosted/cloud PBX redundancy

• using mobile apps

• This makes VoIP more resilient than traditional onsite PBX solutions.

Do I need desk phones?

Not necessarily. Many UK businesses now operate fully on:

• PC softphones

• laptops

• mobile apps

• headsets

Desk phones remain optional, not required.

Do I need special equipment?

• Minimal hardware is needed. At most:

• a router/firewall capable of prioritising VoIP

• handsets or headsets (optional)

• PoE switch (if using physical phones)

Cloud deployments eliminate on-premise server requirements.

Are handsets included?

Handsets can be purchased or leased. Many businesses skip handsets entirely and use softphones, which reduces cost.

Can I keep my existing phone numbers?

Yes, number porting is standard. UK geographic numbers (e.g. 024 Coventry) and non-geographic numbers (e.g. 03/08 numbers) can be retained.

Setup & Support

How much does it cost to set up a VoIP phone system?

Costs vary depending on:

• number of users

• handset requirements

• call bundles

• number of SIP trunks needed (1 SIP trunk allows 1 external call, SIP trunks do not impact internal calls)

However, VoIP generally has lower setup and ongoing costs than ISDN or on-prem PBX hardware. SMEs often move to VoIP for cost savings alone.

Who can help me with my VoIP phone system?

If you're a UK business exploring VoIP, a Managed Service Provider (MSP) is typically the best partner. At Network Ltd, we design, deploy, and support 3CX and SIP-based telephony, including:

✔ installation & configuration

✔ SIP trunk provisioning

✔ number porting

✔ security hardening

✔ ongoing support

✔ remote & hybrid setups

✔ cloud hosting options

Ready to modernise your business phone system?

We can design, deploy, and support a 3CX solution tailored to your organisation.

Click Here to Book a Call with our Phone System Expert Today

Written by Jack Marshall

Date: 09/01/2026