Business phone numbers in the UK and the 2027 landline switch-off
By Future Momentum Systems · Updated October 2026
The UK's old copper phone network (PSTN and ISDN) is being switched off on 31 January 2027. If your business still relies on a traditional landline, now is the time to plan your move – and a good moment to rethink how your calls are answered.
What is the landline switch-off?
BT Openreach is retiring the analogue phone network and moving every UK line to digital (internet-based) calling. The deadline was originally December 2025 and was pushed back to 31 January 2027. Lines that haven't moved by then will stop working.
What it means for small businesses
- Traditional landlines must move to a digital service (VoIP or BT Digital Voice)
- Some older equipment – alarms, card machines, fax lines – may need checking
- Most businesses can keep their existing number when they switch
Types of UK business phone number
- Geographic numbers (01/02) – look local, e.g. 020 for London
- Mobile numbers (07) – simple, but can look less established
- Non-geographic (03, 0800) – national presence; 0800 is free for callers
A local 01/02 number usually builds the most trust for local businesses.
Use the switch to fix missed calls
Moving to a digital line is the perfect time to add call answering. Digital numbers can forward to an AI receptionist when you're busy, so every call gets answered.