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SIP and Business VOIP

SIP Trunking: SIP Compatible Phone Systems


SIP Trunks & SIP Communicator™ Hosted PBX


Spitfire is one of the UK’s leading Business VoIP and SIP specialists, providing all the products and services you need when you’re ready to ring the changes and move your telephone communications to IP and a Next Generation Network.


Switch from traditional telephone lines to SIP trunks or Hosted PBX services, and you can enjoy number flexibility, business continuity and scalability, combined with cost savings of up to 70% compared with ISDN30e.


If you are moving premises or opening a new office, looking to reduce costs or are worried about disaster recovery, you need to speak to us about SIP and Business VoIP. More than 90% of the main office telephone line installations we make are now based on SIP services – and we’ve been using a VoIP network in our own offices for over five years already.


Over 80% of ISDN lines will have moved to SIP by 2019, and with BT Group aiming to move all ISDN customers to IP by 2025, it’s time for you to plan your move.






VOIP/SIP – The key benefits


  • High-call quality, delivered over high-speed Voice Approved circuits
  • Save more than 50% on rental and set up costs compared to ISDN30e.
  • Add new phone numbers from any UK dialling code – regardless of your physical location
  • Integrate home workers as standard.
  • Keep your existing phone number when you move


Call us now on 0800 319 6363 to see how SIP and Business VoIP services can work for you – or select from the following options to find out more.



SIP Trunking

Business SIP Trunks – High Reliability UK SIP Trunking   From £4 per SIP Trunk per month   If you need the flexibility and control of your own phone system – and either already have a phone system or are happy to buy, run and manage the phone system yourself – SIP Trunks are the right […]

SIP Communicator™ Hosted PBX

SIP Communicator™ is Spitfire’s own Hosted PBX – offering unrivalled flexibility and scalability to deliver a system that grows with your business. Enjoy high call-quality, free calls between office sites, and extensions from just £6 per month.

Business SIP Explained

  From £10 per extension per month   Spitfire Cloud 3CX harnesses the power of 3CX, the world’s leading windows based phone system. It offers significant cost savings and improved flexibility compared with an on-premises phone system, and brings an excellent range of Unified Communication features.

Voice Approved

When you upgrade your office internet for a faster, smoother connection, why not take advantage of cheaper, smarter phone calls too – by choosing a Voice Approved Circuit that provides full support for VOIP technology.

At Spitfire, we have a range of Voice Approved Circuits backed by SLAs that promise premium performance. No BT-based DSL circuits come with SLAs supporting ISDN voice quality – and without guarantees you run the risk of poor quality calls, call drops and intermittent/one-way audio.

Enquire Today

For further information on Voice Approved and to talk to one of the team, give us a call on 020 7501 3333 or email us on

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