VoIP vs landline: which is better for business?

What is the difference between VoIP and a landline?

A landline carries your voice as an electrical signal down a dedicated copper wire on the PSTN, the network that has powered UK phones for decades. VoIP carries the same call as data packets over your internet connection instead. The caller hears no difference, but everything behind the scenes changes.

The practical effect is that a landline ties a phone number to a single physical socket in one building. VoIP frees the number from the wall. Because the call is just data, the same number can ring on a desk phone, a mobile app and a web browser at the same time, anywhere there is internet. That is the core reason VoIP suits modern, hybrid and multi-site working far better than copper lines ever could. If you want the full explanation of how the technology works, read what is VoIP and how does it work.

There is also a timing reason this comparison matters now. The UK is retiring the old PSTN and ISDN networks on 31 January 2027. After that date, traditional analogue and ISDN landlines stop working, and every business has to move to an internet-based phone service. So the real question for most companies is not whether to switch, but when.

VoIP vs landline: how do they compare?

The clearest way to weigh the two is feature by feature. The table below sets them side by side on the points that matter to a working business.

Factor	VoIP	Traditional landline
Monthly cost	About £7 to £30 per user, UK calls usually included	Line rental per number plus metered calls
Upfront cost	None for hosted; desk phones optional	Higher, especially with an on-site system
Call quality	HD voice, often clearer than copper	Standard PSTN audio
Features	Auto-attendant, call recording, AI transcription, CRM, apps	Basic calling, limited extras
Mobility	Ring anywhere on app, browser or desk phone	Tied to a physical socket
Scaling	Add or remove users in minutes	Engineer visit to add lines
Reliability in an outage	Needs power and internet; failover to mobile available	Older analogue lines could draw power from the line
Future-proofing	The replacement network	Switched off 31 January 2027

On cost, features, mobility and future-proofing, VoIP is the clear winner for most teams. The one column where a traditional landline historically had an edge is power resilience, and that is now a manageable problem rather than a deal-breaker.

Does VoIP cost less than a landline?

For most small businesses, yes. A landline charges line rental for every number plus per-minute call costs, and an on-premise system adds an upfront hardware bill that can run to £1,000 or more per user. VoIP replaces all of that with a single predictable per-user fee, typically £7 to £30 a month, with UK landline and mobile calls bundled in. Calls between your own staff and sites are free.

The saving grows the more people and sites you have, because there is no per-line rental and no separate maintenance contract. For a five-person team, a hosted VoIP system usually costs around £50 to £90 a month all in. For a full breakdown by team size, see our guide to business phone system costs in the UK.

Where does a landline still have an edge?

It would be wrong to pretend VoIP has no trade-offs. The honest downside is dependence on power and internet. A VoIP desk phone needs both to work, so if your office loses electricity or your broadband drops, the handsets go quiet. An old analogue landline could often draw a small amount of power from the line itself, which kept a basic phone working in a power cut.

In practice this is easily handled. Call failover automatically diverts incoming calls to staff mobiles or another site, a backup 4G or 5G connection keeps the office online, and the mobile app means people are reachable on their own phones during any disruption. A UPS (battery backup) keeps routers and phones running through short outages. So the business stays reachable even when a building does not. We cover the options in detail in what happens to VoIP in a power cut or internet outage. The other thing to remember is that the landline's resilience advantage is a moot point after the 2027 switch-off, because those analogue lines are going regardless.

So which should a business choose?

For the overwhelming majority of UK businesses, VoIP is the right answer. It costs less, does far more and is the network the country is moving to. The features alone (auto-attendant menus, call recording, AI call transcription, CRM logging and even an AI receptionist that answers calls 24/7) let a small team operate like a much larger one, which a copper landline can never match.

A traditional landline only really suits a very narrow set of cases, and even those are running out of road as the PSTN closes. If you are still on copper, the sensible move is to plan your switch on your own terms rather than wait for a forced migration in 2027. You can keep your existing number, set up in days and run both systems in parallel during the changeover. Browse the full set of guides in our Learn hub to plan the move.