What's the difference between per-call and per-minute AI receptionist pricing?
Per-call pricing charges a flat rate every time a call is answered, regardless of call length. Per-minute pricing charges by call duration. The difference shows up in bill predictability and total monthly cost. A 4-minute call on a per-minute plan at $2/min is $8; the same call on a per-call plan at $0.66/call (Aira Premium rate) is $0.66. Across a busy month with longer calls, per-minute bills routinely come in 30–80% above the listed plan price because of overage and long-call inflation. Per-call pricing caps the per-call cost at the plan rate, so the monthly bill is predictable. Aira uses per-call pricing on every plan; Smith.ai, Ruby Receptionists, and most traditional live answering services use per-minute. Per-minute is fine for very short calls or very low volume; per-call wins for any practice with calls longer than 2–3 minutes. See the per-call vs per-minute pricing breakdown.
Per-call vs per-minute — side-by-side
The two pricing models lead to materially different monthly bills for the same call volume, especially when call duration is uneven. The tradeoff is predictability vs theoretically-cheaper-on-very-short-calls.
| Dimension | Per-call (Aira) | Per-minute (Smith.ai, Ruby, traditional) |
|---|---|---|
| How billing works | Flat rate per answered call | By minute, rounded up to next minute typically |
| Effect of call length | Cost is constant — long calls cost the same as short ones | Cost scales linearly with duration |
| Bill predictability | High — number of calls × per-call rate | Low — total minutes vary with call mix |
| Overage handling | Additional calls bill at same per-call rate | Overage minutes typically billed at 1.0–1.25× rate |
| Best fit for | Practices with calls longer than 2–3 minutes; stable budgeting | Very short calls (under 2 min) or very low volume (under 10 calls/mo) |
| Effective per-call cost | $0.66/call (Aira Premium 90 calls) | $2.00–$8.00 per typical 2–4 minute call |
When per-minute makes sense (and when it doesn't)
Per-minute pricing is mathematically advantageous in two narrow cases: very short calls (under 2 minutes — common for spam screening or appointment confirmations) and very low volume (under 10 calls per month, where the fixed cost of a per-call plan exceeds the variable cost of per-minute). Most service businesses don't fit either case.
The hidden problem with per-minute is bill volatility. A practice that averages 100 calls per month at 3 minutes each pays for 300 minutes. The same 100 calls at 5 minutes each pays for 500 minutes — 67% more than the budget assumed. Per-call pricing avoids this entirely: 100 calls is 100 calls. For any practice that needs predictable monthly receptionist costs, per-call wins.
Related questions
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