Best business phone systems for UK small businesses (2026)

Choosing a phone system used to mean picking a box for the cupboard and a set of desk phones. In 2026 it's a different decision — and a more urgent one, because the UK's old phone network is being switched off. This guide walks UK small businesses through the options, the features that actually matter, what it costs, and how to choose the right system without overpaying.

The big deadline: the PSTN switch-off

The traditional PSTN and ISDN network that has carried business calls for decades is being retired, and the network is switched off on 31 January 2027, a date Openreach has confirmed is final (see our article on the PSTN switch-off). If your business still runs on analogue lines or an ISDN system, you need to move to a digital system before then or you'll lose service. The good news: the replacement is cheaper and far more capable.

Plenty of businesses have left it late. At the end of July 2026 Openreach reported around 1.5 million lines still on the old copper network, roughly 350,000 of them business premises.

Waiting is also getting expensive. Openreach has been raising the rental on legacy analogue lines in steps to push migration along — 20% in April 2026, 40% in July 2026 and 40% again in October 2026, which roughly doubles what the same line cost in 2025. Openreach's own position is that in some cases it is now cheaper to be on a modern all-IP product than to stay put.

Why you may not be able to switch like-for-like

This catches people out. There has been a UK-wide stop sell on Wholesale Line Rental since 5 September 2023, so no new analogue lines can be supplied anywhere, and an analogue line cannot be migrated to another analogue line. It also covers broadband that rides on one of those lines, which means you may not be able to move an old ADSL or FTTC service to a new provider "as is".

There is a second trigger too. Once an exchange passes 75% full-fibre coverage, a priority exchange stop sell applies and — where FTTP is available at your address — FTTP becomes the only product that can be ordered. Analogue lines, ISDN2, ISDN30, FTTC and SOGEA all drop off the menu.

Worth being clear about what a stop sell does and doesn't do: it closes the door on new orders. It does not disconnect a working line. Existing services keep running until you move them or the product is withdrawn on 31 January 2027.

The three types of system, compared

Almost every small business ends up choosing between three shapes of system. This is the honest trade-off between them, with no vendor names attached.

	Cloud-hosted VoIP	On-premise IP-PBX	Mobile / SIM-based
How it works	The phone system lives in the provider's data centre. Calls travel over your internet connection to handsets and apps.	A physical system in a cupboard or comms rack on your premises, connected to the internet via SIP trunks.	Business numbers and call features delivered to mobile handsets over the mobile network.
Best suited to	The large majority of small and medium businesses, especially hybrid or multi-site teams.	Larger single sites, or specialist setups with unusual integration or on-site equipment requirements.	Very small teams, or field-based businesses where nobody sits at a desk.
Upfront cost	Low. Often nothing beyond handsets, and staff can use softphone apps on existing devices.	High. You buy and own the hardware, plus installation.	Low. Usually just the handsets.
Ongoing cost	Per-user monthly subscription, scaling up and down with headcount.	Lower per-user, but add maintenance contracts, support and eventual replacement.	Per-SIM monthly, plus data.
Switch-off exposure	None. Already all-IP.	None if it runs on SIP trunks; a problem if it still relies on ISDN.	None.
Who maintains it	The provider, with changes usually made for you or through a portal.	You, or whoever holds the maintenance contract. On-site visits for faults.	The provider.
Main drawback	Depends on a stable internet connection, so the line matters.	Capital tied up in hardware that dates, and less flexible for remote working.	Limited call handling — reception, queues and menus are usually basic or absent.

Desk phones, apps, or both?

Once you've picked a cloud system, the next question is what people actually pick up. You don't have to choose one answer for the whole company, and mixing is normal.

• Softphone apps — the business number on a laptop or mobile. No hardware to buy, ideal for hybrid staff, and fine with a decent headset. Least popular with people who dislike taking calls through a computer.
• Desk handsets — still the right answer for anyone on the phone all day, and for reception. Entry-level models handle calls and transfers; mid-range and touchscreen models add a directory, line keys for colleagues and busy-lamp fields so you can see who's free.
• Cordless or DECT — for warehouses, workshops, salons and anywhere staff move around but need to answer the main number.
• A shared or common-area phone — one handset in a workshop, kitchen or meeting room, without paying for a named user.

One practical point on buying hardware: check whether handsets are locked to the provider before you spend anything. Standards-based SIP handsets can usually be re-provisioned onto a new system, so existing kit is often worth keeping, but provider-locked phones can become landfill the day you switch.

Features that actually matter for a small business

• Mobile and desktop apps — take your business number anywhere, so home and hybrid working just works.
• Call routing and menus — send calls to the right person or team automatically.
• Voicemail-to-email and call recording — never miss a message; keep records where you need them.
• Microsoft Teams integration — make and take calls directly in Teams if that's where your team already lives.
• Simple scaling — add or remove users in minutes as you grow.
• Number porting — keep your existing business numbers when you switch.

What does it cost?

Cloud VoIP is typically £8–£20 per user per month depending on the features and call bundle you choose. Because staff can use softphone apps on the devices they already have (or keep compatible handsets), upfront hardware costs are often minimal. Compared with the line rental and call charges of a traditional system, most businesses save money as well as gaining features.

Do the comparison against what your legacy lines will cost you next year rather than what they cost last year. With the staged increases above roughly doubling legacy rental against 2025, the gap has widened on its own.

It's not just the phones

The most common nasty surprise in a switch-off migration is a device nobody thought of, because anything that quietly dials out over an analogue line is affected:

• Alarm panels and alarm diallers
• Lift emergency phones
• Card payment and PDQ terminals
• Fax machines and modems
• Building management and heating control systems
• Door entry systems

Walk the building and list every socket before you plan the move. A lift line or an alarm dialler discovered late is what turns a tidy migration into an emergency.

How to choose the right system

• Start with how your team works. Office-based, hybrid, or fully remote? That drives whether you need desk phones, apps, or both.
• Check your internet. VoIP needs a stable connection. A quick line check confirms you're ready — our broadband availability checker can help.
• Plan the switch early. Don't wait for the switch-off deadline; porting numbers and setting up call flows is smoother with time.
• Buy from someone local you can reach. When a call flow needs changing, you want a real person, not a call centre.

What to ask before you buy

Take this list to any provider you're speaking to, including us. The answers separate a system that fits from one you'll be arguing with in a year.

• What is the contract term, and what happens at the end of it?
• Are the handsets locked to you, or standards-based SIP I could take elsewhere?
• Who ports my numbers, and what is the plan if the port hits a problem?
• Can I change a call flow myself, or do I have to raise a ticket every time?
• What happens to calls if my internet drops — is there automatic failover to mobiles?
• Is call recording included, and where is the data stored?
• What does it cost to add a user mid-contract, and to remove one?
• Who do I actually ring when something breaks, and what are the hours?

Frequently asked questions

What is the best type of phone system for a small business in 2026?

For almost every UK small business, a cloud-hosted VoIP system is now the best choice. It works over your internet connection, costs less than traditional lines, adds features like call routing and mobile apps, and is future-proof ahead of the PSTN switch-off.

When is the PSTN switch-off and what does it mean?

The UK's traditional PSTN and ISDN phone network is being retired, with the network switched off on 31 January 2027. Any business still on analogue or ISDN lines needs to move to a digital or VoIP system before then to avoid losing service.

How much does a business VoIP phone system cost?

Cloud VoIP typically costs around £8–£20 per user per month depending on features and call bundles, with little or no upfront hardware cost if staff use softphone apps or bring existing handsets.

Can I keep my existing phone number when I switch?

Yes. Established numbers are ported to the new system so customers reach you exactly as before. Porting is scheduled around your business and is the part of the project worth planning earliest, because it depends on the losing provider as well as the new one.

Do I need new handsets to move to VoIP?

Not necessarily. Staff can use softphone apps on the computers and mobiles they already have, and standards-based SIP handsets can often be re-provisioned onto a new system. Handsets locked to a previous provider usually cannot be reused.

What happens to my alarm, lift line or card terminal?

Anything that dials out over an analogue line is affected by the switch-off, including alarm diallers, lift emergency phones, card payment terminals, fax machines and building management systems. Each needs checking and, in most cases, moving to an IP or mobile-based alternative.

Will VoIP work if my internet goes down?

Calls need the connection, so a good setup plans for it losing: routing that automatically diverts to mobiles or another site when the line drops. Ask any provider how their failover works before you sign.

How Tech Savvy Solutions helps

We set up cloud phone systems for businesses across Bury, Manchester and the North West — handling the design, the number porting and the switch from old lines before the deadline. We'll walk the building with you, find the alarm and lift lines before they become a problem, and set the call handling up the way you actually work.