Sip Trunks

The Smart & Cost-Effective Alternative to ISDN

Keeps Your Current PBX Phone System Working

With ISDN services coming to an end, there’s no better time to switch your business phone system to Prosum’s SIP Trunks & low-cost call plans.

SIP Trunks are IP-based connections giving you the flexibility to make calls from your current phone system. They provide the added benefits of low-cost phone calls and are easily scalable to meet your business needs. SIP Trunks are ideal for organisations of all sizes looking for high quality, cost-effective, scalable telephone lines.

SIP Trunk Call Plans

Get reliable connectivity for your PBX phone system with Prosum’s SIP Trunks Plans & low call rates

With flexible PAYG & Unlimited SIP Trunk Call Plans, there’s a solution for every business.

All pricing is ex. GST

Quick & Easy to Setup

Keep Your Number

No Lock-in Contracts

Cancel Plan Anytime

Prosum SIP TrunksPay-as-you-go for all the calls you make every month within Australia.

Starter Bundle

$15.00 mo.

  • Includes up to 5 lines.
  • $3.00 thereafter per SIP Trunk

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

Sip Trunking

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

$53.00 mo.

Per SIP Trunk

13/1300 outbound: $0.30 per call

Prosum SIP Trunks

Keep 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.

Need a custom plan?

Call us on 1800 007 229 for a custom quote.

Why Prosum's SIP Trunks?

Enjoy Immediate Cost Savings

Say goodbye to high phone line rental costs and save with flexible SIP Trunk call plans & low-cost call rates.

Scale as Needed

As your business grows, add additional call capacity quickly & easily when and where you need it.

Experience 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.


Direct Routing for MS Teams

Integrate SIP into MS Teams & transform it into a complete PBX replacement.

Keep Your Current PBX

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



We Help Businesses Like Yours Achieve Success

25+ Years Experience

100% Australian Owned

Carrier-Grade Network

Award-Winning Support

  • "Your team is amazing, extremely helpful and have delivered a product that is second to none"


Switch your business to SIP Trunks and start cutting costs today

Fill out our online form to request a call-back or, call on 1800 007 229 to speak to us directly.