A per-minute rate is only half of a price. The other half is how the seconds are counted. Two routes quoted at the same rate can produce invoices that differ by more than double, and the gap is widest for the short calls dialers make most.
How to read the notation
Increments are written as two numbers: the minimum billed duration, then the block size after that. Every answered call is rounded up to the minimum, and anything beyond it is rounded up to the next full block.
- 1/1: billed per second from the first second.
- 6/6: a 6-second minimum, then 6-second blocks.
- 30/6: a 30-second minimum, then 6-second blocks.
- 60/60: every call is rounded up to whole minutes.
Unanswered calls are not billed on any of these schemes. What changes is how answered seconds are rounded.
Worked examples
The table shows billed seconds for three answered calls, and the multiplier against the true duration. A multiplier of 1.20 means you pay 20% more than the call actually lasted.
| Actual duration | 1/1 | 6/6 | 30/6 | 60/60 |
|---|---|---|---|---|
| 8 s | 8 s (1.00) | 12 s (1.50) | 30 s (3.75) | 60 s (7.50) |
| 25 s | 25 s (1.00) | 30 s (1.20) | 30 s (1.20) | 60 s (2.40) |
| 95 s | 95 s (1.00) | 96 s (1.01) | 96 s (1.01) | 120 s (1.26) |
The pattern is consistent: increments matter little on long conversations and a great deal on short ones. A 95-second call costs almost the same on 6/6 as on 1/1. An 8-second call, such as a quick hang-up after an agent greeting, costs seven and a half times its duration on 60/60.
Why dialer traffic feels this most
Outbound campaigns produce many short answered calls: voicemail greetings, wrong numbers and people who hang up after a few seconds. If a third of your answered calls last under 15 seconds, the increment can move your blended cost more than a small change in rate would.
Short calls also affect quality metrics. A falling ACD can be a sign of answering-machine traffic, list quality problems or false answer supervision on the route. It is worth investigating before you look only at cost.
How we bill
Our rate sheet states the increment next to every destination, so you never have to ask. The full rules for answered-call billing, minimum durations and wallet deductions are on how billing works.