Guide
Pay per call vs per minute: which is cheaper for you
Updated
Almost every guide to this question answers it with a preference. It has an arithmetic answer instead, and the input is not your call volume: it is your average call LENGTH. Per call pricing is a bet that your calls run long. Per minute pricing is a bet that they run short. Below is where the bet flips, using rates published on the providers' own pages.
The crossover is a division, not an opinion
A per call price divided by a per minute rate gives the call length at which the two models cost the same. Smith.ai charges $11.50 for a call over its Starter allowance. Specialty Answering Service charges $1.44 a minute on its 220 Minute plan. Divide one by the other and the crossover is a fraction under eight minutes: below that, the metered provider is cheaper, and above it the per call provider is.
Run the same division against the most expensive published rate here and the picture changes completely. PATLive's BASIC plan is $2.60 a minute, so $11.50 buys about four and a half minutes. If your calls average six minutes, the per call provider is already the cheaper one.
This is why the same two providers can each honestly claim to be better value. They are describing different callers.
Most people underestimate their call length
The instinct is to picture the short call: a caller asking whether you are open. Those exist, but they are not what an answering service is for. The calls that justify the service are the ones where a receptionist takes a full message, qualifies a lead, books an appointment or transfers a live caller to you, and those run minutes rather than seconds.
None of the providers here publish an average call length, so we do not either. What you can do is measure your own: your phone system's call log already has it, and it is the single number that decides which model you should buy. Measuring it takes ten minutes and is worth more than any comparison table, including ours.
What the per call model actually removes
The reason to pay per call is not usually that it is cheaper. It is that it removes an incentive. Under a metered contract, every second a receptionist spends being thorough costs you money, and you will feel it when a good long call appears on the bill next to a bad short one.
Smith.ai prices the call rather than the minute and states no overseas agents, no setup fees and month to month terms with a 30 day money back guarantee of up to $1,000. Committing to 12 months takes 10% off. That is a coherent product for someone whose calls are worth a lot each: a law firm intake line rather than a delivery dispatcher.
Where the allowance hides the real rate
Every plan here bundles something, and the bundle is where the effective rate hides. Smith.ai's Starter is $300 for 30 calls, so an included call is $10.00 and the thirty first is $11.50. Use only fifteen calls and you have paid $20.00 each.
The same trap runs the other way on metered plans. Abby Connect's Essential is $329 for up to 100 minutes, which is $3.29 a minute if you use every one and considerably more if you do not. No overage rate is published, so the cost of a busy month is not knowable from the pricing page.
The honest way to read any of these is to price your own expected month twice: once at the plan you think you need, and once at the plan below it plus overage.