BT announced in 2015 that they are planning a complete ISDN switch off by 2025, in order to provide businesses with more advanced communication options. The question is, however, what is replacing ISDN?

SIP Trunking

SIP trunking is a cost-effective and flexible alternative to ISDN for both outbound and inbound voice calls. With SIP trunking, you’ll be able to achieve more control over your business operations while enhancing your existing data and voice connections. In this blog, we’ll be taking a look at some of the ways in which SIP trunking can help your business move forward.

The Benefits of SIP Trunking

Business Continuity

SIP trunking offers businesses more flexibility than traditional ISDN in order to make your data and voice connections more resilient. SIP trunking can minimise issues such as line damage and office moving to make sure that your business stays intact.

Number Flexibility

SIP trunking gives you the opportunity to choose which number you want to display to contacts on a call-by-call basis. This way, even if your office moves location, you can still use a local area code.


SIP trunking gives you the opportunity to discard any disused ISDN lines and save a significant amount of money on data and voice connection services. The flexibility provided by your changeable SIP trunking number also means that you won’t have to waste money changing advertisements, listings or stationery while offering free calls between connected locations.


If you are using ISDN, it’s likely that you are spending money on lines that you’re not necessarily using throughout the year. With SIP trunking, you can add more lines when demand is higher, reduce them when demand is lower and even split calls to make them more efficient to handle. Being able to make these changes instantly gives you complete control over your communications.

Contingency Plan

Sometimes, things will happen that are out of your control. Whether it is a lack of connection, busy peak times or an issue in the office, SIP trunking offers you a business continuity feature that can reroute any calls automatically in order to back up your sites quickly.

At Staveley Communications, we want to make it as easy as possible for your business communications to function optimally, which is why we can set up SIP trunking for you using your existing ISDN numbers. For more information, get in touch with our team today.

Image source: Unsplash

Staveley Comms
Brighton House
Trident Business Park
Daten Avenue