Most SIP trunk providers hide their pricing behind a “Contact Sales” button. This is not an accident. Hidden pricing means the sales team can quote different rates to different customers based on how much they think you will pay. It means the rate you negotiated last year may be higher than what a new customer gets today. And it means you cannot comparison shop without investing hours in sales calls, demos, and follow-up emails — which is exactly the friction the provider wants to create.
SIPNEX publishes our rates on our website because we are a direct carrier setting our own prices, not a reseller marking up someone else’s rate card and hoping you do not find the original. This guide breaks down SIP trunk pricing into its component parts so you can compare any provider — including us — on an apples-to-apples basis.
The components of SIP trunk pricing
SIP trunk pricing has five components. Some providers bundle them, some itemize them, and some hide the expensive ones in the contract terms. Here is what to look for.
Per-minute rates. This is the core cost — what you pay for each minute of connected call time. Rates vary by direction (outbound vs inbound), destination (domestic vs international, metro vs rural), and volume commitment. US domestic outbound rates range from $0.005/minute (high-volume wholesale) to $0.030/minute (low-volume retail). Inbound rates are typically lower or included. International rates vary dramatically by destination — UK and Canada are cheap ($0.01-$0.03), developing countries can be $0.10 or more.
Per-channel fees. Some providers charge a monthly fee for each concurrent call channel — $0.50 to $2.00 per channel per month. This is an artificial scarcity charge that mimics PRI pricing. If you need 200 concurrent channels for your predictive dialer, per-channel fees add $100 to $400 per month on top of your per-minute usage. SIPNEX does not charge per-channel fees. Channels are unlimited.
DID fees. Monthly charges for phone numbers. Local DIDs: $1 to $3/month. Toll-free: $2 to $5/month. Some providers charge setup fees per DID ($5 to $25 one-time). Some charge for DID features (CNAM registration, E911) that other providers include for free. SIPNEX includes CNAM registration and A-level STIR/SHAKEN attestation as standard with every DID.
Platform or trunk fees. Some providers charge a monthly trunk fee ($10 to $50/month) or a platform access fee. This is essentially a subscription charge on top of usage. It is more common with CPaaS providers and resellers than with direct carriers. SIPNEX does not charge a platform or trunk fee.
Regulatory and compliance fees. USF (Universal Service Fund) contribution, E911 fees, and state/local telecom taxes. These are pass-through charges that every provider must collect — the difference is whether they are itemized or bundled into the per-minute rate. Itemized is more transparent. Bundled is simpler but hides the actual per-minute rate.
The billing increment trap
Billing increments determine how per-minute charges are calculated, and the difference is larger than most operators realize.
6-second billing (6/6). The standard for wholesale carriers. A 47-second call is billed as 48 seconds (8 six-second blocks). SIPNEX uses 6-second billing.
1-minute billing (1/1). Common with retail and some CPaaS providers. A 47-second call is billed as 60 seconds — a full minute. A 61-second call is billed as 120 seconds — two full minutes.
1-minute minimum with 6-second increments (1/6). A 47-second call is billed as 60 seconds (1-minute minimum). A 67-second call is billed as 72 seconds (1-minute minimum + 2 six-second blocks).
The impact at scale: on 1-minute billing, a campaign where the average call duration is 45 seconds (very common for predictive dialing with high AMD rates) overpays by 33 percent compared to 6-second billing. On 100,000 minutes of billed time at $0.01/minute, that is $330 per month in waste. Always ask about billing increments and always do the math with your actual average call duration.
Volume tier pricing
Most carriers offer lower per-minute rates at higher monthly volume commitments. Here is a typical tier structure (actual rates vary by carrier):
Under 100,000 minutes/month: $0.020 to $0.030/minute. This is the retail tier — small businesses, light calling operations. Per-minute rates are highest because the carrier has fixed costs (support, infrastructure, compliance) spread across low volume.
100,000 to 500,000 minutes/month: $0.012 to $0.020/minute. The mid-market tier. Most call centers with 20 to 100 agents fall here. Volume justifies better rates, but you are still a mid-size customer.
500,000 to 5,000,000 minutes/month: $0.008 to $0.012/minute. The wholesale tier. Serious dialer operations. Rates approach wholesale carrier costs. At this volume, the difference between $0.008 and $0.012 is $2,000 per million minutes.
5,000,000+ minutes/month: $0.005 to $0.008/minute. The enterprise wholesale tier. Large operations or aggregators. Rates are near carrier interconnect costs. Negotiations are per-customer and may involve volume commitments.
See SIPNEX published rates for our specific tier structure.
The hidden costs
Number porting fees. Some carriers charge $5 to $25 per number to port numbers in. SIPNEX does not charge porting fees. If a carrier charges for porting, they are monetizing a standard process that costs them almost nothing to execute.
Contract termination fees. Some carriers lock you into 12 to 36 month contracts with early termination penalties. Read the contract. If there is a term commitment, understand the penalty for leaving early. SIPNEX does not require long-term contracts.
Overage penalties. Some carriers offer low per-minute rates tied to minimum volume commitments — use less than the minimum and you pay the minimum anyway. This is effectively a contract with a take-or-pay structure. Fine if your volume is predictable. Risky if it fluctuates.
Support tier charges. Some carriers charge extra for “premium” support — faster response times, dedicated account managers, 24/7 availability. On SIPNEX, support is included. When you call about a VICIdial configuration issue, you get someone who understands the problem without paying for an upgraded support tier.
How to compare providers
When evaluating SIP trunk pricing, normalize everything to a total monthly cost based on your actual usage pattern:
- Estimate your monthly minutes (outbound + inbound)
- Estimate your peak concurrent channels
- Count your DIDs (local + toll-free)
- Calculate: (minutes × per-minute rate) + (channels × per-channel fee) + (DIDs × monthly DID fee) + trunk/platform fees + porting fees (amortized)
- Adjust for billing increment (multiply by 1.33 if 1-minute billing vs 6-second)
- Add regulatory fees and taxes (typically 10-15% on top)
Run this calculation for every provider you are evaluating. The provider with the lowest per-minute rate may not be the cheapest total cost once per-channel fees, platform charges, and billing increment differences are factored in.
Frequently asked questions
What is a fair price for SIP trunking in 2026?
For US domestic outbound on a direct carrier, fair wholesale rates range from $0.005/minute (5M+ minutes/month) to $0.030/minute (under 100K minutes). Per-channel fees should be zero on a modern SIP carrier — if you are paying per channel, you are paying for artificial scarcity. DID fees should be $1-3/month for local, $2-5 for toll-free, with no setup fees. No platform or trunk fees. 6-second billing increments. No long-term contracts. If your provider’s pricing deviates significantly from these benchmarks, you are either overpaying or there are hidden charges you have not found yet.
Why do some SIP providers hide their pricing?
Hidden pricing allows providers to price-discriminate — charge different rates to different customers based on their perceived willingness to pay, their negotiating skill, and their awareness of market rates. It also creates friction that discourages comparison shopping, keeping customers on higher rates longer. Carriers that publish rates (like SIPNEX) do so because the rates are competitive and transparency is a selling point. Carriers that hide rates typically have higher prices, complex fee structures, or both. As a rule of thumb: if you cannot see the price before talking to sales, the price is higher than it needs to be.
Should I choose the cheapest SIP trunk provider?
No. The cheapest per-minute rate often comes with tradeoffs that cost more than the savings: per-channel fees that add up at high concurrency, 1-minute billing that inflates costs by 20-30%, B-level STIR/SHAKEN attestation that reduces answer rates, limited support that costs you time when problems arise, and channel caps that throttle your predictive dialer. Evaluate total cost (including all fees and billing increment effects), attestation level, channel policy, support quality, and reliability. The lowest total cost with A-level attestation and unlimited channels is the right combination — not the lowest per-minute rate in isolation.
Does SIPNEX charge per concurrent channel?
No. SIPNEX SIP trunks have unlimited concurrent channels with no per-channel fee. You pay per minute for actual usage and per month for DIDs. That is the complete pricing model — no channel fees, no platform fees, no trunk fees, no setup fees, no porting fees. Your single trunk handles as many simultaneous calls as your bandwidth supports. This model is ideal for predictive dialing operations where concurrent channel demand bursts unpredictably based on answer rate fluctuations.
SIPNEX publishes transparent wholesale rates because we are the carrier setting the price, not a reseller hiding a markup. No per-channel fees, no platform fees, 6-second billing, A-level STIR/SHAKEN. See the rate card or talk to an operator.
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SIPNEX
FCC-licensed carrier with its own STIR/SHAKEN SP certificate. Operator-owned. SIP trunks built for operators who dial at volume.