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.
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Ask a QuestionHow 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
SIP Trunk Pricing Comparison. Australian Plans (April 2026)
| Budget metered | Mid-range unlimited | Business unlimited | |
|---|---|---|---|
| Channel fee | $4-6/channel/month | $8-12/channel/month | $10-20/channel/month |
| Local/national calls | 1-3c/min | Included | Included |
| Mobile calls (AU) | 8-12c/min | Included or 3-5c/min | Included |
| DID numbers | $2-4/month each | $2-4/month each | $3-5/month each (some included) |
| 1300 numbers | $5-15/month | $8-20/month | $8-20/month |
| Emergency calling (000) | Check: some charge $1-3/month | Usually included | Included |
| Minimum channels | 1 | 2-4 typical minimum | 4-8 typical minimum |
| Contract term | Month to month | Month to month or 12 months | 12-24 months typical |
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.
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.
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 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 is a fair price for SIP trunking in Australia?
Can I use a SIP trunk with any PBX?
Do I need to pay for each phone number separately?
Is there a minimum number of SIP trunk channels?
Does a SIP trunk support 000 emergency calls?
Related reading:
- SIP trunk vs cloud phone system
- How many SIP trunks do I need?
- phone line providers in Australia
- FreePBX setup guide
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Get a RecommendationEvery 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.
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