A call buffer is the minimum amount of connected time a call must reach before it is billed. If a call connects and ends before it reaches the buffer, the buyer does not pay for it. If it reaches or passes the buffer, the buyer is charged.
Why a threshold exists at all
Without a threshold, a buyer would pay for every call that technically connects, including a wrong number that hangs up in one second or a call that reaches voicemail and ends immediately. A buffer sets a floor: enough time has to pass for there to be a reasonable chance a real conversation happened.
How the buffer is measured
Connected time is measured after the buyer's destination number or softphone actually answers. Ringing time does not count. A call is charged once, at the moment connected time reaches or passes the selected buffer. Calls that are never answered, or that end before the buffer is reached, are not billed. Time spent in the buyer's own IVR or voicemail system after the call is answered still counts toward the buffer, because from the platform's perspective the call has connected.
The minimum buffer and how longer ones are priced
On Callmart, the minimum buffer is 10 seconds. A campaign can offer more than one tier, each with its own buffer and price, for example $50 at a 15 second buffer, $60 at a 30 second buffer, and $75 at a 60 second buffer. A longer buffer generally costs more per call, because more calls that would have qualified at a shorter buffer fail to reach a longer one. You are paying more per call for a stronger signal that a real conversation is happening.
Choosing a buffer as a buyer
A shorter buffer generally means a lower price per call and more calls that qualify, including some that end quickly for reasons that have nothing to do with call quality, like a caller who was screened for the wrong product. A longer buffer costs more per call but each one is more likely to represent a real conversation that got somewhere. Which one fits depends on how your team works a call: a fast qualifying flow can make good use of a shorter buffer, while a team doing a full needs conversation on every call may prefer paying more for calls already proven to run longer.
Where buffer shows up before you buy
Callmart shows buyers the price and the connected-time threshold for each campaign available to them before they switch buying on for that campaign, so there is no guessing at what qualifies a call once you turn it on.
How buffer terminology varies across the industry
Some platforms use the word threshold or qualifying time instead of buffer, and some publishers use the term floor to describe the same idea: a minimum connected time a call has to reach before it counts as billable. The underlying mechanic is consistent even when the label is not. When comparing platforms, confirm what a stated price actually requires in seconds, not just the headline number attached to it.
What a buffer does and does not tell you
A call that crosses its buffer tells you it stayed connected for at least that long. It does not tell you what was said, whether the caller was a genuine fit for the campaign, or how the conversation went once it started. Buffer is a timing signal, not a quality score. Pairing buffer data with a habit of reviewing call recordings gives a fuller picture than buffer length on its own.
- You have a fast, practiced opening that qualifies a caller within the first few seconds.
- You are testing a brand new campaign and want to control cost while you learn how it performs.
- Your team has enough capacity that working a higher volume of shorter calls is manageable.
Buffer tiers are set per campaign, not account-wide, so the same buyer can be running a 10 second buffer on one campaign and a 60 second buffer on another at the same time. There is no rule that a buyer has to pick one buffer strategy and apply it everywhere; the right choice is specific to each campaign's call pattern and how your team handles it.
A buffer that is set too long for how your team actually works calls tends to show up as fewer billed calls than expected relative to volume delivered, since more calls end before crossing the threshold. A buffer set too short for a slower, more thorough opening can mean paying repeatedly for calls that end just as a real conversation was starting. Watching how your billed call count compares to your delivered call count over a few weeks is a practical way to judge whether a tier fits.
| Buffer length | General tradeoff |
|---|---|
| Shorter, near the 10 second minimum | Lower price per call, more calls qualify, a lighter signal of engagement |
| Longer, such as 30 to 60 seconds | Higher price per call, fewer calls qualify, a stronger signal of engagement |
Common questions
01Does ringing time count toward the buffer?
No. Connected time starts only after your destination number or softphone answers the call. Time spent ringing before that is not counted.
02What happens if a call ends one second before the buffer?
It is not billed. The call has to reach or pass the buffer, the selected connected-time threshold, for a charge to occur.
03What is the shortest buffer available on Callmart?
10 seconds is the minimum buffer on Callmart. Some campaigns offer longer buffer tiers at a higher price per call.
04Does time in my own IVR count toward the buffer?
Yes. Once the call has answered on your end, any time spent in your own IVR or voicemail system still counts toward the buffer, because the call is already connected from the platform's perspective.