SIP Trunks

The cost-effective, flexible alternative to ISDN. Our SIP trunks work seamlessly with each of the leading IP PBX brands in the UK market. 

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Trusted by 1200+ companies across the UK

SIP Trunks Supplier 

SIP trunks (Session Initiation Protocol) is a more flexible alternative to ISDN, with a lower cost, for inbound and outbound voice calls. While being quicker to install, and provision, SIP also gives your business stronger continuity.

With end-to-end communication SIP is an established way to move your PBX system to the cloud.

Unlike traditional phone lines SIP uses internet or a third party IP network, making your calls local again and drastically reducing costs.

  • 50% reduction on call costs
  • From £5 per channel
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SIP Solutions for your business

If you are a small to large business, there is no need to worry about SIP capacity. From a small PBX of two lines to large call centres SIP trunks are completely scalable. SIP combines both voice and data into a single network making it easier for your employees to work remotely.

With a new monthly SIP plan in place you will instantly see the ROI on your communication costs.

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SIP Trunks - Why Choose IBT?

Savings

- Up to 50% off lines!
- Up to 25% of calls.
- Not only saving you money SIP is a more reliable connection than ISDN.

Flexibility 

Out of the office? Divert to your mobile.
- Expand or condense your services when required.

Control

- Be in control!
- Lines: Add, remove, split, reroute and divert them.
- While saving money!

Future Proofing

 ISDN is set to be switched off in 2025 - SIP is the way forward.

Contingency

Be prepared for the unexpected. With SIP you can easily divert calls, update call features, use video and conference calling and so much more you might not expect to.

Compatibility

Already have a PBX installed? SIP works with the majority of leading brands.

1200+ UK companies use IBT for their communications

See what our customers have to say.
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We gave IBT a chance as a local provider and they impressed us with their knowledge, advice and they really understood our business and how we operate.

We partner with the best

Frequently asked questions

For tailored information, contact us directly and we will happily answer any questions you may have. 

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  • Can I have SIP installed for my business?

    Any business with a PBX can switch to a SIP trunking service. You will immediately benefit from a more flexible, less expensive and more resilient phone service.

  • What is SIP?

    SIP Trunking is a standards-based replacement for traditional ISDN. It connects your PBX to the PSTN via broadband, Ethernet or a private circuit into our national network. SIP Trunks work seamlessly with each of the leading IP PBX brands in the UK market.

  • What does SIP stand for?

    SIP means Session Initiation Protocol. Established in the 90s SIP was developed to set up and terminate VoIP calls and generate a dialling tone.