Alternatives to BT for business phones and broadband
The PSTN switch-off ends BT landlines by January 2027. Compare BT alternatives for business phones and broadband, costs, and how to switch.
The UK's copper phone network is being switched off. Openreach's deadline is 31 January 2027, and it has said the date will not move again. If your business still has BT landlines, an ISDN phone system or an alarm or card machine on a phone line, you have to change something in the next few months anyway. That makes now the right time to ask whether BT is still the best fit.
This guide explains what the switch-off means, what the realistic alternatives are, and how to switch without losing your number or a day of calls.
Key takeaways
- BT landlines and ISDN lines stop working when the PSTN switch-off completes on 31 January 2027.
- BT's own replacement is Digital Voice. You do not have to move to it. You can take your numbers to any provider.
- For most small businesses the best alternative is a hosted VoIP phone system running over full fibre broadband.
- You keep your existing numbers. Number porting is a standard process and usually takes 1 to 3 weeks.
- Check alarms, lifts, door entry, fax and card terminals. These are the things that stop working without warning.
What is the PSTN switch-off?
The Public Switched Telephone Network (PSTN) is the copper network that has carried UK phone calls for over a century. Openreach is retiring it, along with the Wholesale Line Rental product that every traditional landline depends on. After the switch-off, calls travel over the internet using Voice over IP (VoIP).
The original deadline was December 2025. It was pushed back to 31 January 2027, mainly to protect vulnerable home users. Businesses do not get that protection: once a line is migrated or withdrawn, anything that relied on the old analogue signal stops working.
What does the switch to Digital Voice mean for my business?
BT Digital Voice is BT's own VoIP landline service. It plugs a phone into the back of a BT router instead of the wall socket. For a sole trader with one line, that may be enough.
For most businesses with more than a couple of staff, Digital Voice is a like-for-like replacement for a system that was already limited. It does not give you:
- calls ringing on mobiles and laptops as well as desk phones
- call groups, menus ("press 1 for accounts") or out-of-hours routing
- call recording, reporting or missed-call alerts
- an easy way to add and remove users when staff join or leave
Since you have to move off the old network regardless, it is worth choosing the system you actually want rather than the default.
Why are businesses looking for alternatives to BT?
Common reasons we hear from UK businesses:
- Cost. Line rental on every number, plus call charges, plus a separate broadband contract, adds up. A hosted phone system usually prices per user, with UK calls included.
- Hybrid working. Staff work from home or on the road, and a desk phone in an empty office does not help anyone.
- Support. Getting a fault fixed or a number moved can mean long waits with a large provider. Many businesses want one named contact who knows their setup.
- Contract flexibility. Long contracts and per-line fees make it hard to grow or shrink.
The main alternatives to BT
1. Hosted VoIP phone system (best fit for most businesses)
Your numbers live in the cloud. Calls reach desk phones, a mobile app and a desktop app, wherever the person is. You manage users, menus and opening hours from a web portal.
Good for: teams of 2 to 200, hybrid teams, businesses with more than one site.
What you need: reliable broadband (full fibre where available), and optionally desk handsets.
2. Microsoft Teams Phone
If your business already runs on Microsoft 365, Teams can make and receive normal phone calls with an add-on licence and a calling plan or operator connect provider.
Good for: businesses that live in Teams all day.
Watch out for: licensing complexity and fewer call-centre features than a dedicated phone system.
3. Mobile-only
Some very small businesses drop the landline and give everyone a business mobile with a single number front end.
Good for: sole traders and small field teams.
Watch out for: no shared call queues, harder to hand calls over, and personal and business calls getting mixed.
4. BT Digital Voice or BT Cloud Voice
Staying with BT on its new products is a valid option, especially for a single line. Compare it on the same terms as the others: total monthly cost, features, contract length and support.
Alternatives to BT broadband
Your phones now depend on your internet connection, so broadband matters more than it used to.
- Full fibre (FTTP) runs fibre all the way to your building. It is faster, more reliable, and available from many providers other than BT over the same Openreach network, plus alternative networks such as CityFibre, Hyperoptic and Community Fibre in many areas.
- Leased lines give dedicated, guaranteed bandwidth with faster fault fixes. Worth it for larger offices or businesses where downtime is expensive.
- 4G or 5G backup keeps phones and card payments working if the main line fails.
See our guide: What is FTTP and how does it work?
What else stops working at the switch-off?
Check every device that uses a phone line, not just phones:
- intruder and fire alarms that dial out to a monitoring centre
- lift emergency phones and door entry systems
- card payment terminals that dial out over a phone line
- franking machines and fax machines
- older ISDN-based phone systems (PBX)
Most have a digital or 4G replacement, but they need to be swapped before your line moves, not after.
How to switch from BT without losing calls
- List every number and device. Include fax numbers, alarm lines and numbers you have forgotten you pay for.
- Check your BT contract end dates. Early termination fees can apply. Your new provider can often time the move to avoid them.
- Order broadband first if it needs upgrading, so the new connection is live before phones move over.
- Set up the new system in parallel. Users, call groups, menus and voicemail are configured before any number moves.
- Port your numbers. The new provider requests the port. On the day, calls switch over in minutes.
- Test and cancel. Test inbound and outbound calls, then cancel the old lines that are no longer needed.
How PurpleBox can help
PurpleBox sets up hosted business phone systems for UK businesses, alongside the broadband, devices and security they depend on. We handle the audit, number porting, call flows and handsets, and stay as your single point of contact afterwards.
See business communications · Case study: a simpler phone system · Request a callback
Frequently asked questions
When does the BT landline switch-off happen?
Openreach's deadline for retiring the copper phone network is 31 January 2027. Some providers have set earlier dates for their own customers, so check any letters from your current provider.
Can I keep my phone number if I leave BT?
Yes. UK landline numbers can be ported to another provider. The new provider arranges it, and it usually takes between one and three weeks.
Do I have to move to BT Digital Voice?
No. Digital Voice is BT's replacement service, but you can move your numbers to any VoIP provider instead.
Will my alarm still work after the switch-off?
Not if it dials out over a traditional phone line. Ask your alarm company about a digital or 4G communicator before your line is migrated.
Is VoIP call quality as good as a landline?
On a decent broadband connection, yes. Call quality depends mainly on your internet connection, which is why we check broadband before moving phones.
How much does a hosted phone system cost?
Most hosted systems are priced per user per month, with UK landline and mobile calls usually included. The total depends on how many users, handsets and features you need. Contact us for a quote based on your current bills.