Why use SIP trunks?
SIP trunking replaces traditional phone lines with a more flexible way to connect your PBX or application to the public telephone network.
View pricingSIP Trunks for PBX systems, voice platforms, and developers
Direct SIP and IAX2 connectivity with flexible routing, scalable capacity, and full control over how your calls are handled. Built for production environments where reliability matters.
SIP Trunks
Connect your PBX system, softswitch, or application using flexible SIP and IAX2 trunking, with scalable channels, global phone numbers, and optional cloud features.
Customized Plans
Build your own SIP trunking setup based on your requirements, with flexible pricing and an instant quote using our pricing calculator.
Highly Available
Improve resilience with SIP failover, call routing options, and flexible configuration to keep your services running.
Fraud Protection
Protect your account with built-in security controls and fraud prevention systems designed for real-world VoIP deployments.
Flexible Configuration
Connect using SIP registration, SIP peering, or IAX2, giving you full control over how your PBX or platform integrates.
Asterisk & IAX2 Support
Built for Asterisk and other open-source PBX platforms, with full support for SIP and IAX2. We continue to support IAX2 as a core part of our platform.
Add Phone Numbers
Provision UK and international phone numbers, including AU and NZ numbers at local rates, or port your existing numbers to Tel2.
AI Voice Integrations
Connect platforms like Twilio, ElevenLabs, LiveKit, and Vapi to the public telephone network using SIP trunking, with ready-made configurations and webhook support.
Looking to take advantage of AI tools? Cloud PBX lines can be integrated much like SIP Trunks, giving you flexible connectivity alongside built-in AI Voice features.
Built for modern PBX and voice platforms
Our SIP trunks are designed to integrate seamlessly with a wide range of PBX systems, applications, and AI voice platforms using SIP or IAX2.
- Configuration guides and ready-made profiles for popular PBX and AI voice platforms
- Flexible connectivity including SIP registration, SIP peering and IAX2
- Consistent, production-ready behaviour for business-critical voice systems
- Support from a team experienced in real-world VoIP deployments
Tel2 provides the telephony layer that connects PBX systems and AI voice platforms to the public telephone network.
View SIP Configuration Guides View IAX2 Configuration Guide
What is SIP Trunking?
SIP trunking allows businesses to connect their phone system to the public telephone network over the internet, replacing traditional ISDN or analog lines. It enables flexible scaling, lower costs, and integration with modern platforms such as Cloud PBX systems and AI voice applications.
No physical lines
Connect over IP instead of ISDN or analog lines, removing the need for on-site telephony infrastructure.
Scale as needed
Add channels and phone numbers instantly without installation delays or hardware changes.
Built for real usage
Supports PBX systems, softswitches, and voice platforms with consistent, predictable behaviour.
Optional platform features
Combine with Cloud PBX features like call recording, analytics, and AI-powered tools when needed.
SIP Trunks vs Traditional Phone Lines
Traditional phone lines require physical infrastructure and fixed capacity. SIP trunking runs over the internet, allowing you to scale channels on demand, integrate with modern platforms, and avoid legacy limitations.
SIP Trunk Pricing
SIP Trunks include basic call handling features through our platform. Add channels, phone numbers, and optional AI Voice features as needed.
SIP Trunk Line
£2 / month
- Choose a local UK phone number
- Or port your own number
- Includes one calling channel
- Unlimited free inbound calls
- Add optional AI Voice features
- Pay-as-you-go calling rates or choose a bundle
Add-ons
Extra Channel
£1 / month
UK Number
£2 / month
Int Number
£2 / month
0800 Number
£2 / month
Global Calling Bundle
Includes calls to UK landlines, UK mobiles, and 50+ international destinations.
500 mins
£8
1000 mins
£15
2000 mins
£25
4000 mins
£45
6000 mins
£60
SIP Trunk Calculator Terms
Standard plans not quite right? Build your own setup and only pay for what you need.
Custom SIP Trunk Plan
£1 / month + VAT ($0 incl)
- 0 x Phone Numbers - 0 x Cloud Lines - 0 x DDI Lines - 0 x Voice Lines
- 0 x Calling Channels
- 0 x Free Extensions
- 0 minutesmins toll-free inbound calling
- - NZ & AU Fixed/Mobiles
SIP Trunks
- 70+ Overseas Destinations
Broadband
Ready to test our SIP trunks?
Start a free 30-day trial and connect your PBX, platform, or application with full control and flexible configuration.
Contact
Have questions? Please contact us using any of the options below.
Address
Telehouse East, 14 Coriander Ave, London E14 2AA, United Kingdom
Call Us
0800 810 1057