Prosum SIP Trunks connect your PBX to the Public Switched Telephone Network (PSTN) using IP-based technology — no dedicated network required. Your existing phone system stays in place while your voice service is upgraded to a reliable, scalable, business-ready solution.
SIP Trunks For Australian Businesses
Reliable SIP Trunks With Melbourne Based Support
Upgrade your business communications with Prosum SIP Trunks — secure, high-quality voice over IP designed for Australian businesses that need reliability, clarity, and control.
With over 25 years of helping Aussie organisations stay connected, our Melbourne-based team ensures your business calls are always connected, clear, and professionally managed.
SIP Trunk Benefits:
- Clear, reliable call quality
- Flexible call plans with transparent pricing
- Month-to-month terms, no lock-in contracts
- Automatic call diversion if your system goes offline
- Seamless integration with your existing PBX or cloud communications platform
- Real local support when you need help
Get started with Prosum's SIP Trunks today.
Seamless Integration with Your Existing Phone System
Flexibile
Use your current internet provider or bundle with Prosum Business Internet. Scale channels and users as your call volumes grow.
Reliable & Continuous
Calls automatically reroute to a backup site, mobile, or alternate number if your primary system goes offline.
Clear Pricing
Predictable monthly pricing, simple billing, and clear call rates — no hidden fees.
Business Outcomes
Reduce dropped calls, improve team collaboration, and deliver a professional experience for your customers.
SIP Trunk Plans
PAY-AS-YOU-GO SIP TRUNKS
Flexible, usage-based billing
Request PricingCall 1800 007 229
Perfect for businesses with variable call volumes. Pay only for the calls you make, with no lock-in contracts.
Included:
- Calls within Australia at competitive per-second rates
- Melbourne-based support from our experienced team
- Cost-effective for low-volume users
Optional Add-Ons:
- DID Numbers
- Number Porting
UNLIMITED SIP TRUNKS
Predictable monthly cost, unlimited calls
Get Started$30 per SIP Trunk/mo
Ideal for businesses with higher call volumes. Enjoy certainty with a fixed monthly fee and full control over your communications.
Included:
- Unlimited calls to Australian local, national, and mobile numbers.
- Transparent monthly pricing with no hidden fees
- 24/7 Melbourne-based support
Optional Add-Ons:
- DID Numbers
- Number Porting
Pricing is ex. GST.
Not Sure if Your PBX Is Compatible?
Most modern PBX systems work with Prosum SIP Trunks. If you’re unsure, our team can review your setup and provide guidance. We’ll ensure your migration is smooth, reliable, and aligned with your business needs.
Why Choose Prosum?
- 25+ Years Experience: Helping Aussie businesses stay connected with reliable communications.
- Local Expertise: Melbourne-based support ensures real people answer your calls when you need help.
- Transparent Pricing: No hidden fees, no lock-in contracts.
- Flexible & Reliable: Fast setup, call routing to offices or mobiles, and business continuity options.
- Seamless Migration: Keep your existing numbers with minimal disruption.
SIP Trunking FAQs
SIP trunks carry voice calls over the internet instead of traditional phone lines. They connect your PBX or cloud phone system to the PSTN, enabling calls to local, national, and mobile numbers.
Unlimited SIP Trunks: $30 per SIP trunk per month (ex GST) for unlimited local, national, and mobile calls.
Pay-As-You-Go SIP Trunks: Pay only for the calls you make, with standard per-second rates. Call us for a quote. No hidden fees and no lock-in contracts.
Yes. Prosum SIP trunks work with most modern SIP-based PBX and cloud phone systems. Our team can review your setup to ensure a smooth, reliable migration.
Absolutely. We manage the porting process end-to-end, so your numbers remain with your business, with minimal disruption.
Pay-As-You-Go: Best for businesses with variable call volumes — you only pay for the calls you make.
Unlimited SIP Trunks: Ideal for high-volume businesses — one fixed monthly fee with unlimited calls to Australian local, national, and mobile numbers.
New SIP trunks are typically activated within 24 - 48 hours. Porting existing numbers may take longer depending on the current provider, but Prosum manages the process to minimise downtime.
Optional TLS/SRTP encryption is available to secure calls. It is not enabled by default, but Prosum can configure it to protect sensitive communications.
Prosum offers automatic diversion. You provide a diversion number, and calls are automatically rerouted to a backup site, mobile, or alternate number — ensuring your customers can always reach you.
Yes — multiple SIP trunks can be added for different departments, teams, or locations. This makes scaling easy as your call volume grows.
Yes — Prosum provides channel bundles and enterprise options for businesses with high call volumes. Contact our team for a customised quote.
Yes. Calls can be routed to office phones, mobiles, or remote users — perfect for businesses with hybrid work setups.
No. Prosum SIP trunks are month-to-month with no lock-in contracts. You can scale or cancel at any time.
