Ask ten wholesale voice buyers how they compare providers and most will start with the per-minute rate. It is the number on the front of every rate sheet, it is easy to line up in a spreadsheet, and it is almost always the wrong thing to optimise for in isolation. Two providers can quote an identical headline rate to the same destination and deliver completely different economics once jurisdiction, billing increments, minimum durations, and route quality are taken into account. Worse, the provider with the lower headline number is often the more expensive one to actually run traffic through, because the calls that matter do not complete.
This is a practical guide to what really sits underneath a wholesale SIP termination rate, written for the people who have to live with the invoice at the end of the month. If you understand these mechanics, the headline rate becomes what it should be: one input among several, not the whole decision.
Jurisdiction is most of the story
US domestic voice is not billed at a single flat rate. It is rated by jurisdiction — interstate, intrastate, or local — and the gap between those categories is not a rounding error. Intrastate rates are frequently higher than interstate, sometimes substantially, because of how access charges work between carriers within a single state. A rate card that looks aggressive on interstate can be quietly uncompetitive intrastate, and if your traffic skews toward in-state calling, the blended cost you actually pay can be far higher than the number you compared.
The critical question is how a provider decides which jurisdiction a call falls into. The correct method is to derive it from a real LERG table — the industry reference that maps every NPA-NXX block to its LATA, OCN, rate center, and state. A provider that instead guesses jurisdiction from the dialled prefix, or applies a blanket assumption, will bill you inconsistently, and those inconsistencies compound across millions of minutes.
Number portability makes this harder and more important. Once a number ports, its original prefix can be a poor guide to where it actually lives today. That is why serious rating dips the Local Routing Number (LRN) for ported numbers before deciding jurisdiction, and does it on both the calling and the called number rather than trusting the dialled digits. If a provider cannot explain how they handle ported traffic, assume your intrastate minutes are being mis-rated.
Billing increments and minimums
After jurisdiction, the mechanics of how time is measured have the biggest effect on real cost. The same rate can produce very different totals depending on how calls are rounded and floored.
- Billing increment: 6/6 (six-second initial, six-second subsequent), 1/1, and 60/60 produce meaningfully different totals, and the effect is largest on the short calls that dominate many traffic profiles.
- Minimum duration: a high minimum-billable duration quietly inflates the cost of every short, legitimate conversation — a customer-service call that lasts eight seconds should not be billed as sixty.
- Connection fees: a small per-call connection fee looks trivial on the rate sheet and becomes a real line item at scale, especially on high-attempt, short-duration traffic.
None of these are hidden if you ask. All of them are easy to overlook if you only compare the headline rate. Model your actual traffic — average call duration, attempt volume, jurisdiction mix — against two rate cards with different increments and the cheaper headline frequently loses.
Route quality is a cost, not a feature
The cheapest route to a destination is rarely the one that completes reliably, and a completion you do not get is more expensive than a minute you overpay for. Route quality shows up in metrics that never appear on a rate sheet: answer-seizure ratio (ASR), average length of call (ALOC), post-dial delay (PDD), and short-duration counts. A route with poor ASR costs you retries; a route with false-answer supervision costs you customer trust; a route that strips or spoofs caller ID costs you deliverability and, increasingly, attestation.
This is why least-cost routing should never mean simply the lowest number. Done properly, LCR selects the cheapest route that meets a defined quality bar, and fails over automatically the moment a route degrades — in real time, not after your customers have complained. The difference between a rate sheet and a network is exactly this: a rate sheet gives you a number, a network protects your completion rate whether or not you are watching.
Postpaid, prepaid, and the trust question
Commercial terms matter alongside the rate. Prepaid arrangements protect the provider and can suit new relationships; postpaid terms require the provider to trust you and, just as importantly, require you to trust that their billing is accurate. That trust is only reasonable if the underlying rating is correct. This is the quiet argument for dual-leg, jurisdiction-aware rating: when a provider can show that both the origination and termination legs of every call carry a rate and a cost, and that a call is never marked billable unless both legs are priced, reconciliation stops being an argument and becomes a formality.
The questions to ask before you sign
- Is rating dual-leg, and is jurisdiction derived from a real LERG table rather than the dialled prefix?
- Are ported numbers dipped for their LRN, independently, on both the calling and called number?
- What is the billing increment and the minimum billable duration?
- Are there per-call connection fees, and how do they apply to short-duration traffic?
- How is route quality monitored, and specifically what triggers automatic failover?
- Can I see ASR and ALOC per destination over time, not just a sampled snapshot?
Get straight answers to those six questions and you will know more about a provider than any rate card can tell you. A partner who welcomes them is confident their network holds up under scrutiny. A partner who deflects is telling you something too.
Hadlo rates every call dual-leg and jurisdiction-aware, derives jurisdiction from a real LERG table, and dips ported numbers on both legs — so the invoice reconciles to the traffic you actually sent. If you want a rate built around your real traffic profile rather than a headline number, talk to our team.