Agile SIP Trunking

Supporting Microsoft Teams, Webex, 3CX and traditional telephony environments like your PBX.

Diagram showing an active SIP Trunk service connected to Callroute.

What You Get With Callroute SIP Trunking

Highly available SIP trunk solutions for organizations of any size.

Inclusive minutes

Flexible options around inclusive minutes or simply pay for the calls you make

Flexible pricing

Pay as you go month-to-month or fixed annual commitment

Auto scaling

Temporarily burst beyond licensed capacity (conditions apply)

Secure Calling

Ensure your conversations are secure with encryption

Reporting

Detailed call reports enable you to track your usage

Call recording

Record PSTN calls for customer success training & compliance (optional)

Integration

Spread your SIP trunk capacity across cloud and on-premise telephony

Availability

99.99% availability built-in with multi-layered resiliency

Why Choose Callroute SIP Trunking

Using Callroute SIP Trunking, you can connect your phone numbers to the environment of your choice in minutes. You won’t have to worry about porting your numbers ever again.

Streamline

Simplify migrations with our self-service portal.

Availability

Enjoy 99.99% availability with our robust network.

Interoperability

Connect Teams, Webex, 3CX, and your PBX.

Flexibility

Easily map numbers across different services.​

Hybrid SIP Trunk Pricing

Hybrid SIP Trunk – PAYG

£5.95 monthly per SIP channel

Add onto any plan!

Ideal for businesses that don’t make many outbound calls

Hybrid SIP Trunk – 300

£9.95 monthly per SIP channel

Add onto any plan!

Everything you need to enable hybrid telephony for your business.

  • Minimum 5 channels
  • Pay-as-you-go outbound calling minutes
  • No set up fees (excludes number porting)
  • Access to detailed reporting
  • Access to self serve portal to facilitate migrations to Teams or other UCaaS platforms
  • Add call recording for an additional £4.95 a channel
  • Add floating minute bundles – refer to FAQs for pricing

£1 per phone number monthly rental applies.

  • Minimum 5 channels
  • 300 domestic mins (01, 02, 03 and mobiles) per channel inclusive
  • No set up fees (excludes number porting)
  • Access to detailed reporting
  • Access to self serve portal to facilitate migrations to Teams or other UCaaS platforms
  • Add call recording for an additional £4.95 a channel

£1 per phone number monthly rental applies.

What Our Customers Say

  • “Callroute making calling easy.

    We have really enjoyed using Callroute and are moving a lot of our clients to it and would recommend it to others.
    The ease to use while integrating with teams it makes managing the whole process easy along with reports making it easy to view incoming and outgoing calls.”

    Jack

    Junior support technician in UK

    Information Technology & Services, 2–10 Employees

  • “Overall very good. Its a simple product, easy to use. Company good to deal with, quick to respond to issues and knowledgeable support team.

    Quick to assign numbers to users. Very easy to find either free unused number or those that are allocated and who to. Tagging system is useful for reporting.”

    Toby

    Head of Service Management in UK

    Publishing, 1,001–5,000 Employees

  • “Overall, my experience with Callroute was solid. The platform offered strong integration capabilities and simplified several aspects of voice routing and number management. While there were areas that could be more intuitive, the core functionality was dependable and added value operationally.
    What I liked most about Callroute was how seamlessly it integrates with existing communication platforms. It removes a lot of the complexity around voice routing and number management, which makes day‑to‑day operations much smoother.”

    Verified Reviewer

    Verified User

    Insurance, 11–50 Employees

Frequently Asked Questions

Yes, you can try Callroute free with a 14-day trial. No credit card and no commitment required. Your trial includes:

  • 1x UK 0330 number
  • 1x single concurrent call limit
  • Connect up to 4 Microsoft Teams tenants
  • Explore all Callroute Teams Calling features
  • Explore all Orto Teams User Management features

To get started, book a guided setup session so we can tailor the trial to your requirements. All you need is an email address, which you’ll verify during setup.

SIP Trunking replaces the traditional phone line (ISDN or analogue) and typically uses the internet to connect your on-premises phone system (E.G. PBX) to the PSTN.

It’s true that SIP trunking is a widely available service, but Callroute goes beyond simply providing connectivity. We make SIP trunking a strategic enabler for digital transformation rather than a commodity.

  • No set-up fees and flexible contracts: Unlike many vendors, we don’t lock customers into long-term commitments or burden them with upfront costs. Our contract terms can be as short as a 30-day rolling agreement, giving you maximum flexibility.
  • Seamless migration capabilities: One of our biggest differentiators is how we position the Callroute SIP trunk as more than just a voice pipe. Once we are in the calling path, our platform makes it simple to migrate services away from legacy PBXs towards modern cloud calling solutions such as Microsoft Teams Phone or Webex Calling.
  • Click-to-migrate number management: Through the Callroute portal, customers can move phone numbers from one service (e.g., SIP trunk) to another (e.g., Teams) at the click of a button. This eliminates the complexity of number porting projects and makes transformation smooth, low-risk, and fast.
  • Pooled channel capacity across sites: Unlike many providers who allocate fixed channels per trunk, Callroute allows capacity to be pooled. This means you can deploy SIP trunks to multiple sites while sharing overall capacity, ensuring more efficient utilisation and reduced cost.

By combining flexible commercial terms, simplified migration, and innovative capacity management, Callroute elevates SIP trunking from a commodity to a strategic tool for business communications.

By combining flexibility, cost transparency, and powerful migration tools, Callroute transforms SIP trunking from a commodity into a catalyst for cloud adoption.

In 2017 Openreach announced that they are turning off the old analogue based PSTN in 2025. PSTN telephone lines include ISDN which many businesses have, these could be ISDN2 (BRI) or ISDN30 (PRI). Additional information can be found on BT’s website.

No. The SIP channel pricing includes the per-user fee. However, if you still have your PBX (or similar) connected via Callroute, you are still required to pay for the associated channel capacity towards that environment.
There are no set-up costs for SIP Trunks as our platform is self-service. However, there may be costs associated with number porting (if required).
There is no maximum number of phone numbers. Port or buy as many phone numbers as you need.
There is no maximum number of phone lines (channels) per SIP Trunk, you can have as many as you like. There is, however, a minimum count of 5 channels per deployment.
All numbers and associated assignments will be visible in the callroute.io portal. Numbers can be remapped individually or in bulk. Changes take 1 to 2 minutes to take effect.
Yes, this can be viewed in the reporting section of the Callroute.io portal.

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