A VoIP phone system sends your business calls over the internet instead of through traditional phone lines. For a London business, that usually means keeping your 020 number, giving staff the option to answer calls from desks, laptops or mobiles, and managing everything through a web portal rather than a cupboard full of equipment.
The timing matters. The UK’s legacy copper phone network is due to be retired on 31 January 2027, and Openreach has said it will not be delayed again. Any London office still relying on analogue lines or ISDN needs a digital replacement, and moving to a hosted setup is the route most firms take.
This guide covers what is specific to London and what to check before you commit.
Why London Businesses Look at VoIP
London offices have a few traits that make this move attractive. Space is expensive, so a dedicated comms cabinet is a poor use of it. Many firms operate across several sites or from serviced offices and co-working spaces. And hybrid working is common, with staff splitting time between home, the office and client sites.
A Voip phone system in London can handle all of that from one platform. Everyone uses the same business numbers, calls follow the person rather than the desk, and adding or removing users doesn’t need an engineer visit.
Keeping Your London Number
Many London businesses care about their 020 number, because it signals a local presence. In most cases you can keep it through number porting, where your existing number moves to your new provider.
A few practical tips:
Start the porting request early, as timescales can vary
Keep your old service live until the new one is confirmed
Check that every number is covered, including fax lines, alarm lines and secondary numbers
Ask whether you can add extra numbers, such as a non-geographic 03 number, for national campaigns
If you open a new site outside London, you can usually add local numbers without installing new phone lines.
Connectivity in London Buildings
This is the point that most often surprises people. Voice quality depends on your internet connection, and connectivity in London varies widely by building.
Shared and Multi-Tenant Buildings
In a serviced office or shared building, what you can install may depend on the landlord, the building’s existing cabling and what the provider can access. Lead times for new connections can be longer than expected, so ask early.
Choosing the Right Connection
Fibre broadband is a sensible baseline for most small offices. Larger or heavily connected teams may prefer a dedicated leased line for consistent performance. If you’re unsure, ask your provider to review your building and usage before recommending a package.
Protecting Voice Quality
Many business routers can prioritise voice traffic over downloads and backups. Wired desk phones are usually more reliable than Wi-Fi handsets. A short network check before go-live avoids most call quality complaints.
Choosing Handsets and Apps
People often ask which is the best VoIP phone. There isn’t a single answer, because it depends on how your team works.
Desk phones suit reception, sales floors and anyone who spends most of the day on calls. Look for good audio quality, comfortable headset support and simple controls.
Softphone apps suit hybrid and mobile staff. Check that the app is stable on both Wi-Fi and mobile data, because quality varies noticeably between providers.
Cordless IP handsets help in larger offices where staff move around, such as clinics or showrooms.
Ask providers which handset brands they support and whether they sell, rent or let you bring your own.
From Small Teams to Large Organisations
Small Business Phone System VoIP
A small team of three to fifteen people usually needs the basics done well: a clear auto attendant, ring groups, voicemail to email and a reliable mobile app. A hosted phone system for a small business keeps costs predictable, since you pay per user and add seats as you grow.
Larger Organisations
A hosted phone system for a large business has different priorities. Multi-site routing, resilience, user permissions, integration with CRM tools and reporting matter more. Larger firms may also want unified communications features, such as chat and video, in the same platform, and need clear service levels from their provider.
If you outgrow a basic setup, a good provider can scale the same platform instead of forcing a full rebuild.
Planning for Disruption
London businesses deal with disruption that smaller towns often don’t, such as transport strikes, building access issues and severe weather affecting commutes. A hosted system helps because calls aren’t tied to the office.
Still, plan for the weak points:
Set up automatic diversion to mobile numbers if the office loses connectivity
Use a battery backup for your router and key equipment
Consider a secondary connection, such as 4G or 5G, for critical sites
Test your failover rules before you need them
Don’t Forget the Non-Phone Devices
Phone lines often carry more than calls. Alarms, lift emergency lines, CCTV links, door entry systems and card payment terminals may all rely on them. In older London buildings, these can be wired in ways nobody remembers.
Before the switch, list every device and ask each supplier what replaces its phone line. This is one of the most common causes of last-minute problems.
What to Ask a Provider
How will you check my building’s connectivity before I sign?
Can I keep my 020 numbers, and what’s the realistic porting timeline?
What happens during an outage, and who is responsible for failover?
Is UK-based support included, and what are the hours?
What are the contract length, notice period and charges for changing user numbers?
How are call recordings stored, and how do you handle GDPR?
Specialists such as Wavetel Business work with UK organisations on migrations like this, and any good provider should be happy to answer these in writing.
Frequently Asked Questions
What is a VoIP phone system?
It’s a business phone service that sends calls over the internet. A hosted VoIP phone system is run by a provider on their platform, and you manage it online.
Can I keep my 020 London number?
In most cases, yes. Number porting moves your existing number to a new provider, though timescales vary, so start early.
Do I need new phones?
Not always. Softphone apps work on laptops and mobiles, but many older analogue handsets won’t be compatible. Dedicated IP handsets generally give better call quality in the office.
Is VoIP reliable enough for a busy London office?
Yes, when it’s set up properly. That means a suitable connection, voice prioritisation on your router, and a backup plan for outages.
How long does the move take?
Many small businesses can move within a few weeks, depending on number porting and connectivity. Larger or multi-site organisations should allow longer and start planning early.
Conclusion
A VoIP phone system gives London businesses flexible, manageable communications that fit shared offices, hybrid teams and growing sites. The key points are to check your building’s connectivity early, plan your number porting, choose handsets that suit how your team works, and build resilience for disruption.
The practical takeaway is to audit your lines and devices, ask providers detailed questions about connectivity and support, and plan your move well before January 2027. Starting early leaves time to do it calmly and properly.
