Managed SIP Trunking

Cut Costs, Scale Fast, Stay Connected

Replace outdated phone lines with a flexible, cost-effective SIP Trunking solution that grows with your business. AOIT’s fully managed SIP services deliver crystal-clear voice quality, seamless scalability and full business continuity.

Traditional Phone Systems Can’t Keep Up

SIP Trunking lets you move away from traditional ISDN or PSTN lines by routing voice calls over your existing internet connection, without changing your existing PBX hardware.

With AOIT’s managed SIP Trunking, you gain a reliable, enterprise-grade voice service tailored to your specific call volume, coverage and growth goals.

Legacy phone systems are not only expensive, they are holding you back. With the PSTN network being phased out, businesses still reliant on traditional lines face rising costs and mounting compatibility issues.

Industry-wide data from the last 18 months

Dec 2026 deadline for the UK's ISDN and PSTN switch-off
31% of UK businesses switched to VoIP in 2025
6M UK businesses using analogue lines affected by the switch-off

Custom-Fit Voice Solutions

We don't believe in one-size-fits-all. Our SIP Trunking is tailored to your infrastructure, call volume and growth plans.

Built-In Business Continuity

Failover, rerouting and proactive monitoring ensure that your phone lines are never a single point of failure.

Optimised for Cost and Quality

Our SIP services help reduce line rental and call costs while maintaining enterprise-grade voice clarity and connection stability.

Resilient Connections, Backed by AOIT

When it comes to business telephony, having the right partner makes all the difference. AOIT Networks brings over a decade of experience helping SMEs transition to flexible, modern SIP Trunking solutions.

From initial planning and number porting to deployment and ongoing support, we manage your SIP solution end to end.

About Us

What Our Partners Say

Kings Church Gateshead

Unparalleled Customer Service

As a charity it was of great importance to us that we had customer support in regards to the choice of services. AOIT Networks have gone above and beyond to ensure a seamless hosting, service transfer and guidance along the way. In addition to services we applied for through AOIT, they advised we applied for a Microsoft 365 NonProfit license, then aided the set up and provided training to our administration.

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Smashdown Consultants

There to help even if you're not sure what to do!

AOIT are always there to help, even when I wasn't sure what the solution is! A few weeks ago, I tried to call a contact. The outbound call didn't work, so I dropped them a text, and they were unable to reach me either. Having worked with Andrew a few times previously, I decided to get in touch with him, even though it was none of his equipment causing issues.

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Real Reviews From Real Partners

  • Every review here is unedited, pulled directly from Trustpilot
  • From real AOIT clients across the UK, not hand-picked quotes
  • Good or bad, it's all there, because that's the point of transparency
Read All Reviews on Trustpilot

Frequently Asked Questions

SIP Trunking replaces physical phone lines by delivering voice calls over your internet connection, allowing for greater flexibility, reduced costs and better scalability.

Yes. We handle full number porting and routing to ensure a smooth transition with zero disruption to your customers or suppliers.

Most likely, yes. Our SIP service is compatible with a wide range of on-premise PBX systems, and we'll assess your setup to ensure seamless integration.

We build redundancy into every SIP deployment. Automatic call rerouting, backup trunks and optional 4G failover keep your business reachable even during outages.

Yes. SIP can be used to power both office-based and remote setups, especially when paired with hosted voice or cloud platforms like Microsoft Teams.

The number of channels you need depends on how many calls happen at the same time, not your total headcount. As a general guide, a business with frequent call activity might need one channel for every four to six staff, but we size this properly based on your actual peak concurrent call volumes.

No. SIP Trunking connects an existing on-premise PBX to the phone network over the internet, so it suits businesses that want to keep their current phone hardware. Hosted Voice is a fully cloud-based phone system that replaces on-premise PBX hardware entirely.

Ready to Safeguard Your Business?

Let’s build a plan that protects your business and gives you peace of mind. Call us today to discuss your SIP Trunking needs.

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