Per-call billing ($1.50–$3.50 a call) fits fleets with short, simple calls and steady volume. Per-minute ($0.85–$1.50) fits low volume or calls that run long, where you don't want to pay a flat rate for time you don't use. Flat-rate ($300–$1,200+ a month) fits steady, predictable volume where you want one number you can budget.
Answering-service pricing looks complicated on purpose, but there are only three models underneath every quote. Pick the wrong one for your call pattern and you overpay by a third without ever seeing a single bad line item. Here is how to match the model to how your phone actually behaves.
The three models in plain terms
Before you compare a single dollar figure, find out which of these a provider bills on. The same monthly total can hide very different economics depending on the model.
- Per-call: a flat charge each time an agent answers, typically $1.50–$3.50, regardless of call length
- Per-minute: you pay for billable talk time, $0.85–$1.50 a minute, usually with a monthly minimum
- Flat-rate: a bundled monthly retainer for a set volume or block of hours, $300–$1,200+
When per-call wins
Per-call is the cheapest model when your calls are short — a quick booking, a confirmation, a quote request that wraps in under two minutes. If most of your calls are 90 seconds, paying a flat $2 beats paying per minute every time. The risk is the long call: a ten-minute dispute still costs you the same $2, which sounds great until you realize a cheap per-call rate sometimes comes with caps or message-only scope.
When per-minute wins
Per-minute fits two situations: low overall volume, where a flat rate would mean paying for hours you don't use, and dispatch-heavy calls that run long and varied. You pay for exactly what you use. The catch is the monthly minimum and what counts as billable — some providers bill hold time and after-call wrap-up, which inflates a clean-looking rate. Always ask what the meter is actually running on.
Every booking, reservation, and enquiry answered in your brand voice — your customers never know it is outsourced.
When flat-rate wins
Flat-rate is for fleets with steady, predictable volume that want one number to budget against. A bundled $700-a-month plan for overnight dispatch is easy to forecast and usually includes a set volume of calls or hours. It's the right call when you're tired of bills that swing with a busy week — but if your volume is lumpy, you can end up paying for capacity you didn't use in a slow month.
A quick worked comparison
Take 300 calls a month averaging three minutes. Per-call at $2.50 is $750. Per-minute at $1.10 is 900 minutes, about $990. A flat plan covering that volume might be $700. In this case per-call and flat-rate are close and per-minute is the loser — but shorten the calls to 90 seconds and per-minute drops to about $495 and suddenly wins. The model that's cheapest depends entirely on your average call length, which is why you should never compare on headline rate alone.
How to choose without getting burned
Pull one month of call data — total calls and average length — and ask each provider to price your actual numbers under their model. Confirm minimums, setup fees, and what counts as billable. The cleanest path is to make them quote all three ways on your real volume and pick the lowest total, not the lowest rate.