SIP Trunks Explained

If your business has an existing on-premise phone system and isn’t ready to move fully to cloud VoIP, SIP trunks are often the best way to modernise. Here’s what they are and how they work.

What is a SIP trunk?

A SIP trunk is a virtual phone line that connects your existing on-premise phone system to the internet, replacing traditional analogue or ISDN phone lines. It uses the same underlying technology as VoIP, but works alongside your current hardware rather than replacing it entirely.

Why businesses use SIP trunks

Lower call costs compared to traditional phone lines
Flexibility to scale the number of lines up or down as needed, without physical line installations
A practical stepping stone for businesses not ready to fully replace their phone hardware
Works well for businesses with an existing PBX system they want to keep using
Simplifies having multiple sites share a single set of phone numbers and call routing

SIP trunks vs full VoIP

SIP trunks essentially modernise the connection to your existing phone system, while full VoIP replaces the phone system itself with a cloud hosted platform. If your current phone hardware still works well and meets your needs, SIP trunks can be a cost effective way to move away from traditional lines without a full system replacement.

Is it right for your business?

We’ll assess your current setup and advise honestly on whether SIP trunks or a full move to cloud VoIP makes more sense for your business, based on your existing hardware, budget and how your business actually uses its phone system.