SIP Trunk Pricing in Australia: What You Should Actually Pay (2026)

SIP trunking connects an on-premise or self-cloud phone system (Asterisk, FreePBX, 3CX) to the Australian PSTN, giving it phone numbers and the ability to make and receive calls. Pricing is more complex than cloud phone system plans because there are more variables: per-channel fees, per-minute call rates versus unlimited bundles, DID number costs, and emergency calling fees. This guide breaks down current Australian SIP trunk pricing so you know what a fair price looks like and what to watch for in provider contracts.

How SIP Trunk Pricing Is Structured

A SIP trunk bill has three main components. Understanding each prevents surprises at invoice time.

1. Channel fees

Each SIP trunk channel supports one simultaneous call. A 4-channel trunk can handle 4 conversations at the same time. Channel fees are the base monthly cost, typically $4 to $10 per channel per month in Australia for standard plans. Some providers offer unlimited channels (metered on call volume rather than concurrency) but per-channel pricing is more common for SMB-scale deployments.

2. Call costs

Call costs cover the per-minute rates for each call type. Australian SIP trunk pricing distinguishes between:

• Local calls: Calls to numbers in the same geographic area code. Some providers include these free; others charge 1 to 2 cents/minute.
• National calls: Calls to 02/03/07/08 numbers outside your local area. Typically free or 1 to 3 cents/minute.
• Mobile calls: Calls to 04xx numbers. This is where costs vary most significantly, from free (included in bundle) to 10+ cents/minute on metered plans. If your business makes frequent calls to mobiles, this line item matters.
• 1300/1800 calls: Calls to 1300 numbers (caller pays local rate) and 1800 numbers (toll-free). Connecting to 1300 numbers is typically free or very low cost; receiving calls on a 1300 DID has associated origination fees.
• International calls: Per-minute rates to international destinations. Rates vary by destination from 2 cents/minute (New Zealand, USA) to much higher for remote destinations.

3. DID number fees

DID (Direct Inward Dialling) numbers are the Australian phone numbers (02, 03, 07, 08 area codes, or 1300/1800) assigned to your SIP trunk for inbound calls. DID fees in Australia are typically $2 to $5 per number per month for geographic numbers. 1300 numbers cost $5 to $20 per month depending on the number and provider. If you port an existing number, the ported number usually takes on the same DID monthly fee.

Typical Australian SIP Trunk Plans

The key differentiator between budget and mid-range plans is mobile call inclusion. For a business that primarily calls landlines, a budget metered plan at $4 to $6 per channel plus call costs can be the cheapest option. For a business where staff regularly call clients on mobiles (which is most Australian businesses), an unlimited plan that includes mobile calls almost always works out cheaper once you run the numbers on actual call volume.

What a SIP Trunk Bill Looks Like: A Worked Example

A five-person accounting firm in Sydney with moderate call volume is a useful reference. Peak concurrent calls are typically two to three, so a four-channel trunk is appropriate. At a mid-range Australian provider charging $7 per channel per month, channel fees are $28. Two Sydney DID numbers (02 area code) at $3 each add $6. Call costs depend on mobile call volume: businesses making mostly landline calls on a flat-rate plan add $15 to $25 per month in call costs. Full SIP trunk cost: $49 to $59 per month. Add a FreePBX or Asterisk VPS at $20 to $30 per month, and the complete self-hosted solution runs $69 to $89 per month for five staff.For comparison, a managed cloud phone system for the same five staff through an AU provider costs $25 to $45 per user per month, totalling $125 to $225 per month all-in -- including phone lines, hosting, and support. The SIP trunk approach is cheaper, but the gap is smaller than most expect once you factor in VPS hosting and the time cost of managing the system yourself. The economics improve significantly at 10 or more channels, where the per-channel cost advantage compounds.

How Many Channels Do You Need?

Channel count determines how many simultaneous calls your SIP trunk supports. As covered in our how many SIP trunks guide, the formula is based on peak concurrent call demand, not total users. A rough guide:

• Under 10 staff: 2 to 4 channels typically sufficient
• 10 to 20 staff: 4 to 8 channels
• 20 to 50 staff: 8 to 16 channels
• 50+ staff: 16+ channels, model based on actual call data

Use our phone lines calculator to get a more precise figure for your business. Starting with fewer channels and scaling up is always an option, most Australian phone line providers let you add channels on demand without a contract change.

Major Australian phone line providers

The Australian SIP trunk market has a mix of wholesale-focused carriers (minimum volume requirements, lower per-unit cost) and SMB-focused providers (no minimum, simple self-service portals).

Telnyx, A US-headquartered carrier with an Australian PoP in Sydney. Competitive per-channel pricing, pay-as-you-go model with no minimum commitment. Good for businesses that want a straightforward international carrier with AU presence. PJSIP-compatible, good Asterisk/FreePBX documentation.

Symbio Networks, Australian wholesale carrier, focused on resellers and higher-volume deployments. Competitive rates at volume but typically requires a reseller account or minimum monthly commitment. More appropriate for IT providers managing multiple clients than for single-business deployments.

VoIP.ms, Canadian provider with AU DID availability. Popular with FreePBX users due to competitive pricing and comprehensive documentation. Note that the server infrastructure is outside Australia, relevant if data sovereignty is a consideration.

Australian-based providers: Several smaller Australian carriers offer SIP trunking for SMBs. Prices are typically higher than international carriers but offer AU-based support and data residency. Evaluate on a case-by-case basis, the market is fragmented and pricing varies significantly.

Before committing to any AU SIP trunk provider, confirm three things: whether 000 emergency calling registration is included at no extra cost (not all providers include it), whether a test period is available before you commit to a contract term, and what the minimum monthly spend is. Many budget providers carry a $10 to $20 per month minimum that exceeds actual usage on low-volume lines, making them more expensive per call than the per-channel rate suggests.

Hidden Costs to Watch For

Emergency calling (000) fees: Some providers charge a monthly per-trunk or per-DID fee for 000 emergency call capability. This is not universal, some providers include it, others charge $1 to $3 per month per DID. Confirm whether 000 is supported and at what cost before signing up. Legally, your business phone system must support 000 calls. See our NBN VOIP guide for the 000 obligation details.

Number porting fees: Porting an existing Australian number to a phone line provider typically costs $0 to $50 per number. Some providers charge a porting fee per number; others include it. Get this in writing before you start the process.

Inbound origination fees: Calls arriving on your DID numbers consume channels and sometimes incur per-minute inbound origination fees (typically 0.5 to 1.5 cents/minute). Most providers include inbound calls, but verify, especially for high-volume inbound operations.

CODEC transcoding fees: Some wholesale carriers charge extra if your PBX requests a codec that requires transcoding (e.g. you request G.729 but the trunk delivers G.711 and the carrier transcodes). Use G.711 (PCMU/PCMA) on both your PBX and trunk to avoid this.

Minimum usage fees: Some providers have a minimum monthly spend (e.g. $20/month minimum). On low-volume trunks, the minimum can exceed your actual usage cost. For businesses with very low call volumes, confirm whether the minimum applies.

SIP ALG (Session Initiation Protocol Application Layer Gateway) deserves specific attention. It is a feature built into most consumer and small-business routers that attempts to assist SIP traffic passing through NAT. In practice, SIP ALG on common NBN routers rewrites SIP packet headers incorrectly and causes symptoms including calls dropping mid-conversation, inbound calls routing directly to voicemail, and one-way audio where one party cannot be heard. If your SIP trunk has intermittent issues that cannot be explained by overall network quality, disabling SIP ALG in your router administration panel is the first diagnostic step. Most AU SIP trunk providers recommend disabling it during initial setup as standard practice.

SIP Trunk vs cloud phone system: Total Cost Compared

A SIP trunk is only one part of the cost for a self-cloud phone system deployment. The full cost of a self-hosted SIP trunk setup includes:

• PBX software license (free for FreePBX; $400 to $2,000+/year for 3CX depending on tier)
• Server or VPS costs ($600 to $1,500/year for a suitable VPS)
• SIP trunk fees (channels + call costs + DID fees)
• IT management time

Compare this to a fully managed cloud phone system at $30 to $55 per user per month. For under 15 users, a cloud phone system is almost always the lower total cost when IT overhead is included. For 20+ users with in-house IT capability, self-hosting with SIP trunks can be meaningfully cheaper. Run the numbers for your specific scale before deciding. See our SIP trunk vs cloud phone system cost comparison.

SIP trunk pricing is one component of a broader cost comparison between self-hosted PBX plus SIP trunks and fully managed cloud phone systems. Our guide to the best phone system for small business in Australia covers this cost comparison in detail and identifies the team sizes where separate SIP trunks and self-hosted PBX come out ahead of managed cloud.

If you are still weighing up whether to move to internet-based calling at all, our guide to cloud phone systems vs traditional phones for Australian businesses covers the full comparison including cost, reliability on NBN, and the practical considerations for Australian businesses making this switch.

What Most Businesses Get Wrong With SIP Trunks

Over-provisioning channels at sign-up. Most AU SMBs calculate worst-case call volume (every staff member calling simultaneously) and order for that scenario. In practice, a five-person business rarely needs more than three simultaneous channels. Start with two or three, monitor peak usage in the first billing cycle, then scale. SIP trunk channels are elastic in most AU provider plans.

Not confirming 000 support before going live. Emergency calling on SIP trunks requires the provider to register your service address with the Emergency Call Person Registration Number (ECRN) system. Some providers skip this step or charge it as an add-on. A business phone service that cannot call 000 is not compliant with ACMA requirements. Confirm 000 registration is included, in writing, before porting any numbers.

Treating the trunk fee as the total cost. The monthly SIP trunk fee is typically 20 to 40 percent of the full cost of a self-hosted PBX deployment. The complete picture includes VPS hosting ($20 to $60 per month), PBX software licensing (3CX, FreePBX, or Asterisk), firewall configuration time, and ongoing maintenance. For teams under 15 users, a fully managed cloud phone system often costs less once the full comparison is run. See our SIP trunk vs hosted PBX comparison for the full cost breakdown by team size.

Your Next Steps

Before committing to a SIP trunk provider:

• Measure your peak concurrent call volume over a typical week, not headcount, before ordering channels
• Confirm 000 emergency calling registration is included and not a separate add-on
• Ask each provider for their ECRN registration process and get confirmation in writing
• Get a full quote including DID fees, minimum monthly spend, and any codec or transcoding charges
• Run the total cost comparison (trunk + VPS + PBX licensing + maintenance time) against a managed cloud quote before making a decision

What is a fair price for SIP trunking in Australia?

A fair price for a mid-range Australian SIP trunk plan in 2026 is $8 to $12 per channel per month with unlimited local, national, and mobile calls included, plus $2 to $4 per DID per month. Budget plans start around $4 to $6 per channel on metered call costs. Business-tier plans with included mobile calls and AU-based support range from $12 to $20 per channel.

Can I use a SIP trunk with any PBX?

Yes, SIP trunks use the standard SIP protocol and work with any SIP-compatible PBX, FreePBX, 3CX, Asterisk, NEC UNIVERGE, Avaya, Cisco, and others. Confirm that your PBX supports PJSIP or SIP registration (most modern systems do) and that the codec preferences are compatible with your trunk provider.

Do I need to pay for each phone number separately?

Yes, DID numbers are typically charged separately at $2 to $5 per number per month for geographic numbers (02/03/07/08). 1300 numbers cost more, $5 to $20 per month depending on the number. Ported numbers usually take on the same DID monthly fee as newly assigned numbers.

Is there a minimum number of SIP trunk channels?

Most Australian SMB-focused phone line providers start at 1 channel with no minimum commitment. Some enterprise-focused or wholesale providers require 4 to 8 channels minimum. For a small business, look for a provider with a 1 or 2 channel minimum and month-to-month terms so you can scale based on actual usage.

Does a SIP trunk support 000 emergency calls?

Most reputable Australian phone line providers support 000 calls, but confirm this explicitly before signing up. Some providers charge a small monthly fee for 000 capability. You must register your physical address with the provider for emergency location purposes, VOIP 000 calls transmit the registered address, not a GPS location.

Related reading:

• SIP trunk vs cloud phone system
• How many SIP trunks do I need?
• phone line providers in Australia
• FreePBX setup guide

Every SIP trunk setup has different costs depending on call volume, channel count, and provider. A small 3CX installation with 5 channels costs very differently from a setup handling 50 simultaneous calls. Tell us your setup details and we'll give you a specific cost estimate. We reply personally. Not a bot, not a form letter.