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VoIP vs landline for small business: what actually changes when you switch
For decades a business line meant a copper pair from the phone company into your building. Today most business calls travel over the internet instead, and in many countries the old network is being switched off. Here is what genuinely changes when a small business moves from a landline to VoIP, what stays the same, and what to check first.
The short version
A landline carries your calls over the phone company’s own wires to a fixed socket. VoIP (voice over internet protocol) carries them as data over an internet connection, so the “line” is no longer tied to a socket. Your number can ring on a mobile app, a laptop or a desk phone, anywhere with a connection.
Why this is coming up now
Phone companies in many countries are retiring their copper networks and moving every line onto digital, internet-based technology. In the UK, for example, BT says the old analogue network switches off on 31 January 2027. Even where no date is set, new business lines are increasingly delivered digitally. For many businesses the question is less “whether” than “how, and when it suits us”.
Side by side
| Traditional landline | VoIP | |
|---|---|---|
| Where calls ring | Phones plugged into the line | Mobile app, browser or desk phone, anywhere online |
| Adding a line | An engineer visit or a new order | Usually a setting |
| Team features | Need a separate phone system on site | Menus, ring groups, voicemail and more come with the phone system |
| Power cut at the office | Some older lines keep working | Office equipment stops; mobile apps on cellular data keep working |
| Call quality depends on | The copper line | Your internet connection and network |
| Emergency calls | Location tied to the line’s address | A registered address you keep up to date |
What stays the same
- Your numbers. In most countries you can keep them. Ask your provider about moving them to a VoIP line, or whether your current provider can deliver the same numbers digitally.
- How people dial. A good system lets your people dial exactly as they did before, and rewrites numbers the way the provider needs.
- Your callers’ experience. They ring the same number and hear a person, a greeting or a menu. They cannot tell what carries the call.
What to check before you switch
- Your internet connection is reliable during working hours, and has room for your busiest call times.
- Your office network and firewall allow call audio. Test a call on office Wi-Fi, not just on mobile data.
- Alarm systems, lift phones, card terminals and fax machines that use the old line have a plan of their own.
- Every person who might dial an emergency number has a registered address in the new system.
- People can still take calls on mobile data if the office internet or power fails.
- You know who to call if something breaks: your provider for the line, your phone system for everything else.
Two ways to go VoIP
An all-in-one hosted service sells you the phone system, numbers and minutes together. Simple, but your numbers and rates are tied to that vendor.
A phone line plus a phone system. A provider sells you a SIP trunk: the line and the numbers, delivered over the internet. You connect a phone system of your choice to it. It is the digital version of what larger businesses did with a phone line and an office switchboard, and it keeps you free to change either part. Our plain-English guide explains what a SIP trunk is.
Switching in five steps
- List your numbers, where each one rings today, and anything else on the old line.
- Choose a provider for the line, or ask your current one for a SIP trunk.
- Set up the phone system and connect the line before you move any number.
- Put the app on your team’s phones and test calls in and out on every number.
- Move numbers one at a time, at a quiet moment, and keep the old line until everything has run for a week.
Is VoIP right for you?
If your people move around, if you want calls to reach the right person without a switchboard, or if your old line is being retired anyway, the answer is almost certainly yes. The real work is not the technology but the checks above. Do those, and most businesses find the day they switch is a quiet one.