What You Are Actually Being Billed For: Rounding, Hold Time, and Spam Calls

Yes. On a per call or per minute answering plan, a robocall that lasts nine seconds can land on your invoice as a full billable unit, and hold time can be billed at the same rate as talk time. The billable unit is rarely the conversation itself. It is a rounded block of connected time.

We read five answering service pricing pages on August 4, 2026. Not one of them publishes a rounding increment. That is the number that decides your invoice, and it is the number nobody prints.

What is a billable unit, and why does it decide the invoice?

Every answering vendor bills against one of four units: per minute, per call, per unique customer, or a flat monthly fee. The unit is the headline. The definition underneath it is where the money moves:

• The rounding increment. Per second, 30 second blocks, or rounded up to the next full minute.
• Which clocks start and stop. Ring time, hold time, transfer time, and after call note entry each either count or they do not.
• What counts as a call at all. Robocalls, spoofed local numbers, wrong numbers, and hangups under 20 seconds.

Two vendors quoting the same per minute rate can produce invoices 20 percent apart on the same call log. Here is that arithmetic.

How much does the rounding increment actually cost?

Standing assumption on this site: average handle time is 3 minutes of talk. Take 40 calls in a month. Add 20 seconds of ring and hold to each one and the clock is running for 200 seconds per call.

• Actual talk time: 40 x 180 seconds = 7,200 seconds, or 120 minutes.
• Actual connected time: 40 x 200 seconds = 8,000 seconds, or 133.3 minutes.

Now bill it three ways:

• Per second: 133.3 billable minutes.
• 30 second blocks: each call rounds up to 210 seconds. 40 x 210 = 8,400 seconds, or 140 billable minutes. That is 5 percent above connected time and 17 percent above talk time.
• Rounded up to the next full minute: each call bills 4 minutes. 40 x 4 = 160 billable minutes. That is 20 percent above connected time and 33 percent above talk time.

Same calls, same work, a 26.7 minute spread. Ruby publishes $720 for 200 receptionist minutes (ruby.com/pricing, read 2026-08-04), which is an effective $3.60 per minute. At that rate, 26.7 minutes of rounding consumes about $96 of your allowance every month for zero additional work. At 400 calls a month instead of 40, the spread is 267 minutes.

Does hold time count as talk time?

Sometimes the vendor tells you, and the answer is broader than you expect. Nexa publishes this definition on its pricing page: "Receptionist work time includes live answer talk time (when a receptionist is on the phone with your client), after-call follow up, email services, scheduling services post-call, dispatching services, and any time spent working on your behalf" (nexa.com/pricing, read 2026-08-04).

Run that against the example above. Add 60 seconds of after call note entry into your CRM and the 200 second call becomes 260 seconds. On a next full minute plan it bills 5 minutes instead of 4. Same customer, same booking, 25 percent more on that line item.

Ask whether the clock stops when the caller does. Then ask it again about wrap up.

How many of the calls you are billed for are junk?

Cactus reports that on one roofing customer's line, 701 spam calls were blocked out of 3,969 total inbound calls in the reporting period. That is 17.7 percent of inbound volume on that one account. It is one customer's number, not a category average, and your own line will read differently.

Run 701 spam calls through a next full minute plan and every one is a full billed minute, even at 20 seconds connected. That is 701 billed minutes and zero customer contact.

The short hangups are harder to catch than the obvious robocalls, because they look real in a report. A phone number tapped on a mobile screen by accident, a back button misfire, a wrong number: each of those opens a connection, and a connection is what most plans bill against. If you run Google Ads, set the minimum call length on your call conversion action high enough that a stray tap does not get counted as a lead. A per call answering plan will count it as a call regardless of what your ad platform decides.

The number that settles a vendor comparison is not the per minute rate. It is cost per booked job. Your booking rate and your average ticket are inputs only you can supply. Put your own numbers in and compare vendors on what a booked job costs, not on what a minute costs.

What do the vendors actually publish?

Competitor prices read from each vendor's public pricing page on August 4, 2026.

Two of the five do address junk calls in writing. Smith.ai lists "No charge for spam" on its pricing page (smith.ai/pricing, read 2026-08-04). Goodcall bills per unique customer and states that "Robo calls, numbers you block, or callers who never say anything to your agent will never count towards your allowance" (goodcall.com/pricing, read 2026-08-04). Those are the published positions as of that date. Vendor terms change, so read the page yourself before you sign anything.

What are the five questions to ask?

1. What is the rounding increment, to the second?
2. Is hold time billed at the same rate as talk time?
3. Is after call note entry or wrap up time billed?
4. What happens to a 9 second hangup? Billed, or not billed?
5. Is spam billed, and who decides what counts as spam, me or you?

Get the answers in an email before you sign. A vendor that will not put the rounding increment in writing will not put a credit on an invoice either.

How do you audit the invoice you already have?

1. Ask for the call detail record with connected duration in seconds, not rounded minutes. If they cannot produce seconds, you already have your rounding answer.
2. Sort by duration ascending and count everything under 20 seconds. That is your junk floor.
3. Divide total billed minutes by total connected minutes. On the example above, 30 second rounding gives a ratio of 1.05 and next full minute rounding gives 1.20. Near 1.0 means you are paying for conversation. Well above it means you are paying for rounding.

Does any of this change after hours?

The volume mix changes at night and so does the junk ratio. 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. That 58 percent belongs to that one company, not to the industry and not to every Cactus account.

Still, if a real share of your capture happens after 6 pm, confirm the billing definition for overflow and after hours calls is the same one you were quoted for business hours. Ask specifically. The same applies during an HVAC heat wave call surge, when volume spikes and a coarse rounding increment compounds against you on every single call.

What should you hold Cactus to?

The same five questions, in writing, before you sign. Cactus list price is $999 per month.

One structural note that touches question three: Cactus books jobs natively into Jobber and Housecall Pro, and the AI creates the job during the call rather than after it. There is no separate after call wrap up clock to bill you for. If you want the mechanics of that, see how AI receptionist booking works with Jobber and Housecall Pro.

If you are weighing an AI answering setup against a human receptionist desk, start with how an AI receptionist works for contractors. If you run a roofing crew and spam volume is your specific problem, see AI receptionist for a roofing company.

FAQ

Am I billed for spam calls on an answering service? It depends on the vendor's definition, and most do not publish one. Smith.ai lists "No charge for spam" on its pricing page. Goodcall bills per unique customer and publishes that robocalls, blocked numbers and callers who never speak to the agent do not count toward your allowance. Ruby, Rosie and Nexa publish no spam definition on their pricing pages, read August 4, 2026, so you have to ask.

What is a rounding increment and why does it matter? It is the block of time your vendor bills in. On 40 calls with 3 minutes of talk plus 20 seconds of ring and hold, per second billing is 133.3 minutes, 30 second blocks is 140 minutes, and rounding up to the next full minute is 160 minutes. Same calls, a 20 percent spread.

Is hold time billed as talk time? Often yes, and it is rarely stated up front. Nexa publishes that receptionist work time includes talk time, after-call follow up, scheduling after the call, dispatching, and any time spent working on your behalf. Adding 60 seconds of after call notes to a 200 second call pushes it from 4 billed minutes to 5 on a next full minute plan.

Does a 9 second hangup count as a billable call? On many per call plans, yes, because the plan bills a connection rather than a conversation. Misdials, back button traffic and stray taps on a mobile phone number all open a connection. Ask the vendor for the exact second threshold below which a call is not billed, and get it in an email.

How do I check my current invoice for this? Ask for the call detail record with connected duration in seconds rather than rounded minutes. Sort ascending, count everything under 20 seconds, then divide billed minutes by connected minutes. A ratio near 1.0 is conversation. A ratio near 1.2 is rounding.

Next step

Book a demo and bring your last answering service invoice with the call detail record behind it. We will walk the two documents against each other on the call and show you, line by line, which minutes were conversation and which were rounding.