Cost Per Booked Job: Where a Flat Fee Passes Per-Call Pricing
Cost per booked job is the monthly fee divided by the jobs that land on your schedule. Not calls answered. Not messages taken. Jobs on the board.
Cactus is $999 per month and the fee does not meter per call or per minute. At 250 inbound calls a month and a 30 percent booking rate that is 75 booked jobs, so $999 / 75 = $13.32 per booked job. At 500 calls the same fee spreads across 150 jobs, or $6.66. At 100 calls it is $33.30 across 30 jobs. The fee holds still while the denominator moves.
Per-call and per-minute plans behave the other way. Their cost per booked job stays roughly level while the invoice climbs with volume. That is why a crossover exists.
Vendor rate detail, including what each plan tier includes, is on AI receptionist for contractors. That page is the price reference. This one is the arithmetic.
What are the inputs, and which ones are yours?
| Input | Value used here | Where it comes from |
|---|---|---|
| Average handle time | 3 minutes | Site-wide modeling assumption; turns calls into minutes |
| Booking rate on inbound calls | 30 percent | Your input. Replace it. |
| Average ticket | $450 | Your input. Replace it. |
Booking rate and average ticket are not research findings. Pull the booking rate from your own call log and the ticket from your last 90 days of invoices. Both move every result on this page.
At what call volume does per-call and per-minute pricing pass $999?
Smith.ai. The published Basic plan is $810 per month for 90 calls with $10.50 per call after that. ($999 - $810) / $10.50 = 18 overage calls. 90 + 18 = 108. Per-call billing passes the flat fee at about 108 inbound calls a month, roughly 3.6 calls a day.
Ruby. The published $720 plan covers 200 minutes. At 3 minutes a call that is 66 calls. Ruby does not publish an overage rate on its pricing page (ruby.com/pricing, read 2026-08-04), so call 67 cannot be priced from public information. The next published rung that covers it is $1,725. There is no slope between the two, only a step, and that step lands above $999 at about 67 calls a month.
Competitor prices read from each vendor's public pricing page on August 4, 2026.
So the crossover is not 500 calls a month. It sits between roughly 67 and 108 calls, which most trades shops clear in a normal week.
Where does the flat fee cost more?
Below that crossover, and against the entry tiers of the lower priced AI tools, $999 is the larger line item.
Goodcall's published ladder tops out at $249 per month for 500 unique customers with $0.50 per unique customer after. ($999 - $249) / $0.50 = 1,500 on top of the 500 included, so it does not reach $999 until about 2,000 unique callers a month. Goodcall bills per unique customer rather than per call, so how many inbound calls that equals depends on your repeat caller rate, which only your phone records show.
Rosie's published ladder tops out at $299 per month for 2,000 minutes. Rosie does not publish an overage rate on its pricing page (heyrosie.com/pricing, read 2026-08-04), so above 2,000 minutes, about 667 calls at 3 minutes each, the price is not public.
If your decision is monthly cost alone and you are under 100 calls a month, a flat fee is the more expensive choice. Nothing about the framing changes that.
Why booking rate decides more money than the fee does
At 250 inbound calls a month, one percentage point of booking rate is 2.5 booked jobs. At a $450 ticket, your number and not ours, that is $1,125 in revenue.
Now run the fee against the same yardstick. $999 divided by a $450 ticket is 2.22 jobs. 2.22 jobs out of 250 calls is 0.89 of a percentage point. The entire $999 is paid for if the option you choose books 0.9 points better than the one you passed on, across the same calls. Everything above that line is margin.
Run it on your own numbers before you sign anything. Divide the difference between two fees by your average ticket to get jobs, then divide by your monthly call count to get percentage points. If the answer is under one point, price is not the deciding variable.
What the fee number does not include
A message taken is not a job booked. If the option you are pricing hands you a transcript instead of a scheduled appointment, your real booking rate is below the one you assumed. Cactus creates the job during the call in Jobber and Housecall Pro. See booking into Jobber and Housecall Pro.
Spam bills like a customer. On a per-call plan every robocall is a billable event, and on a per-minute plan the pickup meters. See answering service billing and spam calls.
After hours is where the uncaptured volume sits. Cactus reports that a plumbing and HVAC company in Utah booked about $150,000 in confirmed revenue in four months, and that about 58 percent of those captured leads came in after hours. Cactus reports that a roofing company in North Carolina collected about $299,000 in ten weeks. Those are figures Cactus reports for those two customers, not audited industry results. See after hours calls in home service.
Volume is not flat. A freeze or a heat wave does not raise call count by 10 percent, and per-call billing compounds in the exact week you are already stretched. See what a heat wave does to the phones.
Next step
Bring your own numbers: real call count, real average ticket, current booking rate. We will run this calculation with you and show you where your crossover sits, including the cases where a lower priced tool wins.
Common questions
How do you calculate cost per booked job for an answering service?
Divide the monthly fee by the jobs that reach your schedule, not by calls answered. At $999 per month, 250 inbound calls and a 30 percent booking rate, that is 75 booked jobs and $13.32 per booked job. Substitute your own call count and booking rate.
At what call volume does a $999 flat fee cost less than per-call pricing?
Above roughly 108 inbound calls a month against Smith.ai's published Basic configuration of $810 for 90 calls plus $10.50 per call after, and above roughly 67 calls against Ruby's published ladder at a 3 minute handle time. Below those volumes, per-call and entry tier AI plans cost less. Prices read from each vendor's public pricing page on August 4, 2026.
Why can I not find Ruby's or Rosie's overage rate?
Neither publishes one. Ruby does not publish an overage rate on ruby.com/pricing and Rosie does not publish one on heyrosie.com/pricing, both read on August 4, 2026. Get the overage rate in writing before you sign.
Does per-unique-customer billing change the math?
It can. Goodcall bills per unique customer per month rather than per call, so repeat callers and callbacks add no cost while a marketing push that brings new names does. Its published ladder tops out at $249 per month for 500 unique customers with $0.50 each after, so it reaches $999 at about 2,000 unique callers a month.
What should I actually compare vendors on?
Booking rate, and what gets written into the scheduler. At 250 calls a month and a $450 ticket, 0.89 of a percentage point of booking rate covers the entire $999 fee, so a fee difference smaller than that is not what decides the outcome.