If your business still uses traditional landline phones, there's a deadline you need to know about: BT is switching off the UK's Public Switched Telephone Network (PSTN) by January 2027. Every business using traditional copper-line telephone services will need to migrate to an internet-based alternative before that date.
That alternative is VoIP - and for most businesses, the switch is not just necessary but genuinely beneficial.
What Is VoIP?
VoIP stands for Voice over Internet Protocol. Instead of sending your voice over a dedicated copper telephone line, VoIP converts it into digital data packets and sends it over the internet - just like email or a web page.
From the user's perspective, it works like a normal phone call. You dial a number, the other person picks up, you talk. The difference is that instead of a physical phone line running into your office, you need a reliable internet connection and either:
- A VoIP desk phone - a physical handset that connects via your network rather than a phone socket
- A softphone - an app on your computer, tablet or mobile that makes and receives calls
- Microsoft Teams Voice - if your business uses Teams, your Teams app becomes your phone system
Why Are Businesses Moving to VoIP?
The PSTN switch-off is the trigger for many businesses to move, but VoIP has been the superior business phone option for years. The reasons businesses choose it:
Cost savings
Traditional ISDN lines typically cost £30–£80/line/month. VoIP costs £5–£15/user/month for a hosted system. For a business with 10 lines, that's a potential saving of £250–£650/month. International calls are also dramatically cheaper over VoIP.
Flexibility and remote working
A VoIP number isn't tied to a physical location. Your staff can make and receive calls on their business number from anywhere - at home, at a client site, or abroad - on any device. This is now essential for hybrid and remote-working businesses.
Scalability
Adding a new phone number or extension in a traditional system requires a phone engineer and a new physical line. On VoIP, it's done in minutes through a web portal. Scaling down is equally frictionless - no contract penalties for reducing lines.
Advanced features included as standard
Enterprise phone features that used to cost thousands of pounds in hardware - hunt groups, call queues, IVR (press 1 for sales...), call recording, voicemail to email, call analytics - are included as standard in most hosted VoIP plans.
What Is Microsoft Teams Voice?
For businesses already using Microsoft Teams, Teams Voice (also called Microsoft Teams Phone) is worth serious consideration. It adds full PSTN calling capability to Teams - meaning your Teams app becomes your complete phone system.
Benefits of Teams Voice for Microsoft 365 users:
- One platform for calls, video meetings, messaging and file sharing
- Calls ring simultaneously on desktop, mobile app and desk phone
- Seamless integration with your Microsoft 365 contacts and calendar
- Call queues, auto-attendants and voicemail all managed within Teams Admin Centre
- Existing Microsoft 365 licences partially cover the cost
Teams Voice requires a Microsoft Teams Phone licence (from £7/user/month) plus a calling plan or direct routing setup. CloudHost manages this for several businesses across the East Midlands - it's particularly well-suited to businesses that are already deep in the Microsoft ecosystem.
What Are the Requirements for VoIP?
VoIP relies entirely on your internet connection. Requirements:
- Bandwidth: Each simultaneous call uses approximately 100kbps. A business with 10 concurrent calls needs 1Mbps dedicated to voice - well within the capacity of most business broadband or leased line connections.
- Quality of Service (QoS): Your network should be configured to prioritise voice traffic over other data. Without QoS, call quality can suffer during periods of heavy network use.
- Reliability: VoIP requires a reliable internet connection. If your broadband goes down, so do your phones. Many businesses add a 4G/5G failover connection for resilience.
- Low latency and jitter: High latency (delay) and jitter (variability in delay) cause poor call quality. A good business broadband or leased line connection will typically meet these requirements; poor-quality consumer broadband may not.
Before switching: Have your IT provider assess your internet connection's suitability for VoIP. A connection that works fine for general internet use may have too much latency or jitter for good voice quality, particularly at peak times.
Number Porting: Keeping Your Existing Numbers
One of the first concerns businesses raise is whether they can keep their existing phone numbers. The answer is yes - through a process called number porting.
Your current phone numbers are transferred to your new VoIP provider. This typically takes 2–4 weeks and is handled entirely by your IT or telecom provider. You keep your existing numbers, and your clients notice nothing.
What Does the Switch-Off Mean for You?
BT's PSTN switch-off in January 2027 means:
- Traditional copper landlines and ISDN services will no longer work
- Businesses still on these services will lose their phone lines entirely
- Devices that use the phone network (alarm systems, CCTV diallers, fax machines, lifts) will also be affected and may need replacing
There's no reason to wait until 2027. Businesses that plan their migration now avoid the inevitable rush as the deadline approaches, and begin benefiting from cost savings and flexibility immediately.
If you're based in Nottingham, Derby, Leicester or anywhere in the East Midlands and want to understand what a move to VoIP would look like for your business, book a free consultation with the CloudHost team.