Having a robust telephone system is one of the most important assets to any business. Multi line telephone systems have long been the go to option for businesses, but what are they and why are they going out of fashion?
What is a Multi Line Telephone System?
A multi line telephone system is a phone system that can sustain multiple calls at once. This means that a number of different staff members can be on the phone at any one time.
Traditionally, a business would have multiple telephone lines running from their premises to the local telephone exchange. These lines would carry individual calls, which means that if 5 people were on the phone simultaneously, then you would need at least 5 telephone lines.
These multi line telephone systems use a technology called ISDN. ISDN is a copper network that connects each call, and runs through the local telephone exchange. In 2025, the UK is switching off its ISDN network, which means that these traditional multi line telephone system will cease to work.
What are the alternatives to multi line ISDN telephone systems?
As technology advances, many businesses are switching from a multi line ISDN phone system to a VoIP telephone system—which does not require multiple telephone lines.
VoIP uses your businesses existing broadband connection, rather than individual copper ISDN telephone lines. This means that your business doesn’t need to pay for multiple telephone lines, helping reduce your running costs.
VoIP can also sustain multiple calls on this one connection, so you don’t need to worry about simultaneous calls backing up.
Is VoIP better than a multi line telephone system?
VoIP is a great replacement for multi line telephone systems for the following reasons:
- VoIP is cheaper than a multi line telephone system
- The ISDN switch off will not affect VoIP
- There are little to no call charges for VoIP
- VoIP enables more features than multi line telephone systems
- Switching to VoIP improves home working
- There is no physical on-premise telephone system with VoIP, saving on hardware costs
Should I buy a multi line telephone system?
If you’re looking to upgrade your business telephone system, then a multi line telephone system is not a good option in the modern day. They’re outdated, costly and when the ISDN network is switched off, you may well struggle with compatibility.
We would recommend looking into VoIP telephone systems. It is a great alternative to multi line telephone system and they are often cheaper in the long run.