TNBN is Britain’s leading Business Digital and IP Phone Company. We connect schools, hospitals, banks, shops, libraries, broadcasters, governments and businesses - large and small - to the world

Openreach have announced that they will be switching off the traditional singe analogue, analogue multiline, ISDN2 and ISDN30 channels during December 2025 with its replacement being FTTC Broadband and SIP Trunks should you wish to make and receive phone calls over VOIP. The UK is to switch to a single IP network connectable by SIP Trunks delivering faster, clearer and more cost effective communications for voice, data and video.

TNBN is here to help you make the migration as simple and straight forward as possible.

How will you connect? (see your options below)

Reduce your cost with a Panasonic IP / SIP enabled on-site telephone system.

  • Buy outright or get this system FREE on a 5 year term

  • Connects to traditional phone lines and SIP Trunks

  • Built in Auto Attendant, Voice Mail, Hunt Groups and Out of Hours mode

  • Fixed price telephone lines and SIP Trunks

Cloud Based UC Office PBX.

  • Free UK Local, National and Mobile calls

  • No office phones needed unless required - use soft App based phones on your device or desktop

  • Fixed monthly cost from £9.99 per user

  • Keep Your Existing Telephone Number

TNBN Superfast UNLIMITED Business Broadband.

  • From just £14.99 per month

  • FREE High Powered WIFi Router

  • 99.99% Always ON connection

  • Voted 5 starts by our customers

Why is SIP the future replacement for Multi lines & ISDN and how will the change benefit you?

  • Lower costs – both rental and calls reduced by up-to 70%

  • Keep your existing phone numbers

  • 99.99% Resiliency using fail over data centres

  • Re-route calls to mobiles and landlines in seconds

  • Scale lines up and down quickly

  • Set call spend perimeters for dial through fraud prevention

PAYG SIP Trunks only £7 each per month

UK Calls 1ppm and UK Mobiles 5p per minute

Bundled SIP Trunks only £15 each per month

3000 UK landline minutes & 2000 mobile minutes pm

How will Sip trunks alter the way you make and receive calls compared to ISDN or Multi Lines?

Your current IDSN set-up

  • Handsets

  • Your phone system (PBX)

  • On-site IDSN box

  • Your office

  • Telephone exchange

Your future SIP set-up

  • Handsets

  • Your phone system (PBX)

  • On-site router

  • Your office

  • Data Centre