Sip Trunks

Keep your phone system ringing with Prosum's SIP Trunks

Prosum’s SIP service is a smart and cost-effective way to connect your existing PBX phone system to the PSTN. SIP Trunks are IP-based connections allowing you to make calls from your existing phone system. They are highly scalable and will seamlessly grow alongside your business. So as your business expands and higher call volumes are required, you can quickly and easily add more lines and users.

Who is it for?

Small Business

10 – 100 Staff

Medium Business

100 – 500 Staff

Large Organisation

500+ Staff

Prosum’s SIP service suits small to large organisations looking for high quality, cost-effective, scalable telephony access.

Prefer to move away from your aging onsite PBX? Simplify your communications with a Cloud phone system easily and affordably.

sip trunk benefits

 Cost Savings

Your business benefits from an affordable connection, reducing line rental fees and call charges.

Highly Scalable

Welcoming new staff or expanding to another site? Make changes quickly & easily when & where needed.

High-Quality Calls

Your private, dedicated bandwidth with QoS ensures your voice calls are always heard crystal clear.

Keep your calls flowing

Unplanned disruptions? Redirect your calls to your chosen recovery site or mobile number of your choice.


24/7 Support Desk

Our 24/7 support teams are based across Australia and available around the clock.

*Keeps Your Current PBX

No need for costly hardware updates. Our SIP Trunks ensure broad compatibility.



*Prosum’s SIP service provides a high-quality SIP Trunk over the internet or a dedicated connection connecting to an IP-based or a legacy ISDN phone system. If you are not sure your PBX phone system will work with our SIP Trunk service, please get in touch with our team; we’re happy to check for you.

SIP Trunk Call Plans

nec for sip trunksPAYG Starter Bundle

Pay-as-you-go for all the calls you make every month within Australia.

$15.00 mo.

  • Includes up to 5 lines.
  • $3.00 thereafter per line.

Call Rates

  • Local calls: $0.10 per call
  • National calls: $0.05 per minute
  • Fixed to mobile: $0.13 per minute
  • 13/1300 outbound: $0.30 per call
There are no lock-in contracts. All our plans are billed monthly. All pricing is ex. GST.

nec for sip trunksUnlimited Starter Bundle

Make unlimited calls to local, national & fixed mobiles within Australia.

$53.00 mo.

  • Includes 1 line.
  • Unlimited calls.

Call Rates

13/1300 outbound: $0.30 per call

There are no lock-in contracts. All our plans are billed monthly. All pricing is ex. GST.

nec for sip trunksKeep or purchase numbers.

  • Single DID Number: $1.00 month
  • 100 DID numbers: $35.00 month
  • Transfer your number to Prosum: $195.00 once-off cost*

*Number porting is subject to your existing carrier’s number porting arrangement.

There are no lock-in contracts. All our plans are billed monthly. All pricing is ex. GST.

To learn more about our SIP Trunks and plans, please speak to a SIP expert on 1800 007 229, or fill out our online form to request a call-back.

Why Australian Businesses Choose us

Prosum is a specialist in delivering SIP Trunks to businesses nationally via our national carrier-grade network. We are committed to delivering innovative solutions across different platforms and tailor these solutions to your needs.

25+ Years Experience

Going Strong

Carrier-Grade Infrastructure

Highly Reliable & Secure

Award-Winning Support

Friendly Local Team

  • Aitken Real Estate had to move office and sought Prosum's advice about switching our telephony to the cloud. Extremely helpful, no-nonsense information and can get the job done. Their tech Antoine was sensational. No delays, no problems. Highly recommend!


Other Solutions You Might Be Interested In

Cloud Phone System

Cloud Phone System

Simplify your communications in the cloud easily and affordably.

Australian Inbound Numbers

Australian Inbound Numbers

Broaden your business reach with 1300/1800 inbound numbers.

Business-Grade Internet

Business-Grade Internet

Accelerate your business performance with super-fast internet.