An AI receptionist or a part-time CSR? The cost math for a 10-truck shop

The AI receptionist vs CSR cost question has a surprising answer: on price per minute of conversation, it isn't close. A part-time customer service rep at the national median wage costs about $27 an hour once benefits and payroll taxes are counted, whether the phone rings or not. AI voice runs on usage, and published list prices put a three-minute call well under a dollar. If cost per minute were the whole story, every shop would fire its front desk tomorrow.

It isn't the whole story, and the shops that treat it that way find out quickly. This post does the full math for a 10-truck shop, then gives you a way to decide which hours of the week should belong to a person, which to AI, and where each one backs up the other.

What a part-time CSR really costs

Start with the wage. The Bureau of Labor Statistics put the median hourly wage for customer service representatives at $21.53 in May 2025, about $44,770 a year for full-time work.¹ Your market may be higher or lower; use your own offer.

Then add what the wage doesn't show. The BLS Employer Costs for Employee Compensation survey for June 2026 found wages and salaries were 80.0% of total compensation for part-time private industry workers, with benefits (paid leave, insurance, legally required costs like Social Security, Medicare and unemployment insurance) making up the other 20.0%. For full-time private workers, wages were 68.5%.²

Not in the table: recruiting, the weeks it takes a new hire to book confidently, the shift nobody covers when they're sick, and turnover. Those are real but vary too much to put a national number on. Put your own figures in.

What an AI receptionist costs

AI voice is priced by the minute of conversation. Twilio lists inbound calls on a local number at $0.0085 a minute and ConversationRelay, its real-time voice service that connects a phone call to an AI model, at $0.07 a minute.³ The AI model and the voice itself add more. TradesWork estimates the all-in cost of its AI receptionist at about $0.14 a minute on its faster model and $0.20 on the most capable one, or $0.40 to $0.60 for a typical three-minute booking call.⁴

Other AI receptionist products price differently: some charge per call, some bundle minutes into a monthly plan, some add a platform fee. Convert whatever you're quoted to cost per minute of conversation so you can compare.

The number that matters: cost per minute of conversation

Comparing an hourly wage to a per-minute price is apples and oranges. Convert the human to the same unit by dividing by how much of each hour is actually spent on calls.

A small-shop CSR rarely talks for more than half of a shift. The rest goes to booking, confirming, callbacks, chasing parts and helping the dispatcher. Here's what that does to the per-minute cost of the phone part of the job.

At realistic talk time, a person costs five to ten times more per minute of conversation than AI. That's the honest headline. The rest of this post is about why it still isn't the decision.

The 10-truck worked example

All volumes here are examples. Pull your own from your phone system.

Say the shop takes 1,000 inbound calls a month, averaging 3 minutes each: 3,000 minutes of conversation. One full-time CSR and the owner's spouse cover the office today.

On cost alone, options B and C are almost free next to a hire. Option D is still cheaper than the part-time hire. So why would anyone hire?

How much worse can the AI book before the savings disappear?

This is the calculation most comparisons leave out. Say you were thinking of using AI instead of the part-time hire to answer the calls that person would have taken. Keep the same example numbers.

• The part-time CSR works 25 hours a week at 30% talk time: about 1,950 minutes of calls a month, or 650 three-minute calls.
• AI handles those minutes for about $390 a month at $0.20 a minute. Savings: about $2,520 a month.
• Assume half of those 650 calls need service (325 calls) and each booked job is worth $250 in gross profit. Every point of booking rate is 3.25 jobs, or about $810.

$2,520 ÷ $810 is about 3 points. If the AI books those callers just 3 percentage points less often than a good CSR would, the savings are gone, before you count the follow-up calls and membership sales the person would also have made. If it books as well or better, which is plausible for routine calls at 7 a.m. or during a lunch rush, the savings are real.

That's why the right test isn't a demo. It's a month of booking rate, measured the same way for both.

What the AI doesn't do between calls

Look at what your CSR did last Tuesday. Most of it wasn't answering the phone.

• Outbound work. Calling unsold estimates, booking due maintenance visits, confirming tomorrow's jobs, calling back the 10 p.m. price shopper. Many AI receptionists, including ours, don't make outbound calls.
• Upset customers. A callback complaint or a billing dispute needs someone who can listen, apologize and make a call about what to do.
• Judgment calls. "Can you squeeze in my mother's furnace today?" depends on things the schedule doesn't show: which tech is closest, who's running long, how you feel about this customer.
• Selling. A good CSR mentions the membership, books the estimate for the 20-year-old system, and notices the caller's neighbor is a customer.
• Everything else. The walk-in, the parts pickup, the tech who needs a customer's gate code.

A person who does all of that well is worth far more than $27 an hour. A person who only answers the phone at 25% talk time is the most expensive way to answer a phone.

The cover-or-back-up model

Instead of "AI or human," decide for each block of the week which role AI plays.

• Cover: AI does the job on its own because no one is there. Nights, weekends, holidays, the lunch hour in a one-person office.
• Back up: a person owns the job, and AI catches what slips. Calls that ring out while your CSR is on another line, leads that arrive while they're booking, after-hours callers who become a callback task for the morning.

Map your week against the 168 hours.

The hours the CSR owns are only 27% of the week. The other 73% is where AI coverage is cheapest and most useful, because the alternative is voicemail.

When to hire instead

Hire, or add hours, when you see these in your numbers:

• Calls ringing out during business hours on most days, not just peak days. That's a staffing gap, not an overflow problem.
• Unsold estimates and due membership visits piling up because nobody has time to call.
• Booking rate on human-answered calls falling as volume rises.
• Customers asking for "the person I talked to last time."

When AI is the better first move

• Fewer than about 20 after-hours calls a week, where a person's on-call time costs more than the work.
• Overflow that happens a few hours a week during heat waves and cold snaps, not every day.
• A one-person office where lunch, appointments and sick days leave the phone uncovered.

Quality: measure both on the same scorecard

Cost is easy to compare. Quality is where owners guess. Don't. Grade AI calls and human calls against the same checklist: greeting, verifying the customer, understanding the problem, offering a real window, asking for the booking, mentioning the membership, and closing.

Then compare booking rate on calls that needed service, separately for AI and human, and listen to the not-booked calls from each. You'll usually find the AI is more consistent on the script and worse at the unusual call, and that your CSRs are better at the unusual call and skip steps when busy. That tells you where each belongs.

A note on where the job market is headed

BLS projects employment of customer service representatives to fall 5% from 2025 to 2035, while still expecting about 289,500 openings a year as people change jobs or retire.¹ That's a national figure across every industry, not a forecast for trade offices. Our view: for most trade offices the sensible move isn't replacing the front desk with AI. It's keeping your best people on the work that needs a person and stopping the bleed of calls nobody was there to answer.

How this works in TradesWork

The TradesWork AI receptionist is in early access and runs in three modes that match this model: after hours only, after hours and when the office doesn't answer (you set how long the office phones ring, 10 to 60 seconds), or every call. Calls it can't book become callback tasks for your team, the settings page shows the estimated cost per minute for your setup, and call scorecards can grade AI calls on the same scorecard as your CSRs. It doesn't make outbound calls. For the other jobs AI can cover or back up, see the AI overview, and for the after-hours side of the math, our post on what after-hours calls are worth.