SIP Trunking from £7.95 a month including 5000 01,02,03 & UK Mobile minutes

Cirrus IT Services (UK) are delighted to announce that our SIP Trunk prices have been reduced and now include 5000 01,02,03 & UK Mobile minutes with each line for free, meaning most users will never pay for calls again!

What is a SIP Trunk?

In a nutshell, SIP Trunks are the Internet connection equivalent to a BT ISDN (digital) line.

SIP trunks allow you to connect your Telephone system to the public telephone network through your internet connection so you don’t need to use ISDN2 or ISDN30 connectivity from BT.

Why would I want one?

SIP trunks are popular as they allow businesses to save money (monthly rental is cheaper and the calls on a SIP trunk are either free or cost less) and they’re flexible (they can be moved from premises to premises and can be scaled up or down depending on demand and they do not require long term fixed contracts)

BT recently announced that ISDN connections will be phased out by 2025 as users migrate to this new technology (

How many would I need?

You would need 1 SIP trunk for every simultaneous call in or out of your system.

If you use 1 ISDN2 2 channel line then you can usually make or receive 2 simultaneous calls so 1 ISDN 2 channel line = 2 SIP Trunks

If you use an ISDN30 connection you can have up to 30 calls in or out at any one time (but can order less) so check how many calls you can handle now to see how many SIP trunks you would need.

If you would like further information, please get in touch today

t: 0330 3500 252 | e: