If you’re making do with ISDN phone lines with your business at the moment, you’re missing out on a cheaper, more resilient and futureproof alternative.

SIP (Session Inanimation Protocol) trunks are virtual phone lines that use your broadband connection to connect your PBX (business phone system) to the traditional phone network. This will become the new standard for phone lines when BT switches off the ISDN network in 2027.

SIP trunks allow you to choose any geographic telephone number – ideal for local marketing campaigns, and they’re much more reliable than ISDN lines which can be hit-and-miss in terms of call quality. They also cost less overall per connection.