BT One Phone has closed. Here is what to move to.
BT One Phone gave staff one business number on a mobile and a desk phone, run from the mobile network. BT confirmed its closure for March 2026 and has been moving customers to BT Cloud Voice. If you are looking for a BT One Phone alternative that keeps the one-number idea without a long new contract, this page compares the options plainly.
Providers are compared on what each publishes: list prices and the conditions attached to them, minimum terms and mid-contract rises, what the price includes (calls, set-up, porting, support hours), UK-based support, and whether failover is offered. Telexico’s own entries are our list prices. Where a provider has changed its terms since the date shown, the published source wins; tell us and we will correct it.
Compiled and reviewed by Mickey Mall, Director, Telexico Communications Ltd, Wolverhampton. Updated October 2026.
Why BT One Phone customers are looking for alternatives.
BT One Phone was unusual: instead of an app, it worked at mobile-network level. Staff had one business number that rang on their mobile and their desk phone, with calls carried on the mobile network and the option of improved coverage inside the building.
In September 2025 BT confirmed on its business forum that the service would close in March 2026, with local sales offices contacting customers about replacements. BT and its partners point One Phone customers to BT Cloud Voice, BT Cloud Voice with BT Business Mobile, or Microsoft Teams Phone through BT.
Three things make people pause before signing. The replacement is a different kind of product (an internet-based system, not a SIM-based one), the new agreement typically runs for several years with its own price-rise terms, and the forced move is a natural moment to ask whether BT should still be the supplier at all.
The main BT One Phone alternatives in 2026.
Each suits a different kind of business. Our own recommendation is first; we have said plainly who the others are for.
Telexico cloud phone system with the Telexico Mobile App
Our pick for most former One Phone customers: a managed hosted system where every user has one business number on a desk phone, in the browser and on the Telexico Mobile App. One per-user price quoted in writing, rolling 30-day terms available, no mid-contract price rises, your numbers ported, and a named UK engineer who set it up. Add business mobile SIMs on the major UK networks if staff also need a mobile plan from the same bill.
BT Cloud Voice (BT’s own replacement)
A capable hosted system and the path of least resistance if you want to stay with BT. Check the term length and the annual price-rise clause before you sign, and confirm exactly how your existing numbers move across.
BT Cloud Voice with BT Business Mobile
The closest to the old mobile-first idea within BT: a hosted system plus BT mobile plans. You get the single supplier back, but it is still app-based calling with a mobile contract alongside, not the network-level set-up One Phone had.
Microsoft Teams Phone
Sensible if your business already lives in Microsoft 365 and wants calling inside Teams. Works well for office teams; less natural for shop floors, vans and reception desks. Telexico can supply Teams calling too, so this is not an either/or.
Self-service VoIP (bOnline, Yay.com and similar)
Cheap and quick for a micro business happy to set everything up itself. No on-site install, no local support, and porting several numbers yourself is where it usually gets painful.
Mobile-only with a business SIM fleet
Some small teams simply move everyone to business mobiles. Fine for a van-based trade, but you lose queues, menus, call recording and the ability to answer the main number from anywhere.
What you had, what BT offers, what we offer.
The honest version, including the one thing a cloud system does differently from One Phone.
| What matters | BT One Phone (closed) | BT Cloud Voice | Telexico cloud phone system |
|---|---|---|---|
| One business number on mobile and desk | Yes, at network level | Yes, via app | Yes, via the Telexico Mobile App, desk phone and browser |
| Calls on the mobile without data or WiFi | Yes (SIM-based) | No, app needs data or WiFi | No, app needs data or WiFi; business SIMs available for the mobile plan itself |
| Coverage inside the building | Optional in-building cell | Depends on your network | Calls over your business WiFi, which we design and install |
| Queues, menus, recording, wallboards | Included | Included | Included |
| Keep your numbers | — | Yes | Yes, ported and tested before cut-over |
| Contract and pricing | — | Multi-year terms; check the annual increase clause | One per-user price quoted in writing; rolling 30-day terms available; no mid-contract price rises |
| Who supports you | BT | BT or a BT partner | A named UK engineer at Telexico |
| Broadband, WiFi, failover and CCTV from the same team | No | Partly | Yes, one relationship and one bill |
The one thing to be clear about: One Phone rang a mobile with no app and no data because it lived on the SIM. Every mainstream replacement, BT’s included, is now app-based. If a member of staff spends the day somewhere with no mobile data and no WiFi, plan for that with a business SIM and call forwarding rather than assuming the app will cover it.
How the switch from BT One Phone works.
1. Review
Send your last One Phone bill, or the BT Cloud Voice proposal. We list your numbers, users and features and tell you what we would change, what it costs and whether staying with BT is the better move.
2. Build alongside
We configure the new system, ship desk phones and set up the Telexico Mobile App while your current service keeps running. Nothing is switched off early.
3. Port and cut over
Your numbers port across on an agreed date (usually one to three weeks from authorisation), with the old and new systems tested side by side. Your named engineer stays with you afterwards.
Six questions to ask about the BT replacement.
1. How long is the new term, and what happens to the price each April? 2. Are early termination fees from One Phone being waived, and is that in writing? 3. Which of our numbers move, and who owns them afterwards? 4. What replaces the in-building coverage we relied on? 5. Is mobile device management still included, or an extra? 6. Who do we ring when something breaks, and how quickly do they answer?
If the answers are good, stay. If they are vague, that is your signal to compare. We will tell you honestly if BT’s offer is the better deal for your set-up.
The services behind the comparison.
Business phone systems
Hosted cloud calling with the Telexico Mobile App, Web UC and desk phones.
Business mobile
Business SIMs on the major UK networks, on the same bill as your phones.
Microsoft Teams calling
Make and take calls inside Teams, with a proper phone system behind it.
Managed business WiFi
Reliable WiFi calling indoors starts with a network designed for it.
Alternatives to BT Business
The wider picture if you are reviewing broadband and lines as well as phones.
The PSTN switch-off
What the end of analogue and ISDN lines means for the rest of your set-up.
BT One Phone alternatives: your questions.
Can we keep our BT One Phone numbers if we leave BT?
Yes. UK business numbers can be ported to another provider. We handle the paperwork, agree a porting date with you and keep the old service running until the new one is tested.
Will staff still have one number on their mobile?
Yes. The Telexico Mobile App presents your business number on the mobile for incoming and outgoing calls, with transfers, presence and voicemail. It needs mobile data or WiFi, which is the main practical difference from One Phone.
What about mobile coverage inside our building?
App calls run over WiFi indoors, so good business WiFi matters. We survey and install managed WiFi where needed, and we can supply business SIMs on the network with the best signal at your address for the mobile plan itself.
Is Telexico a long contract like the BT replacement?
We discuss the term openly before you sign and we do not raise prices mid-contract. Tell us what you have been offered and we will set out the comparison in writing.
How long does moving from BT One Phone take?
The system can be configured and phones shipped in days; number porting usually completes one to three weeks after authorisation depending on the line type. Most businesses switch with no downtime because both systems run in parallel until cut-over.
Can you also replace our BT broadband and lines?
Yes. Phones, full fibre or leased lines, WiFi, 4G/5G failover and CCTV can all sit under one Telexico relationship and one bill, which is often the point of making the move now.