A technician leaves one service call and spends the next 40 minutes driving across torwn, waiting for access, and picking up materials for the next job. At a T&M billable labor rate of $45 to $75 an hour, that’s $30 to $50 in unbilled revenue before a wrench is turned [Angi, 2025]. Every minute is on payroll, but much of that time never appears in job costs, invoices, or margin reports.

Margin erosion rarely happens on a single service call. It usually shows up in the gaps between calls.

A supply run, a wait for access, twenty minutes between calls. None of it looks like a problem in the moment. It all disappears into payroll without ever being tied back to a client, a job or a clearly defined overhead activity.

The Cost of Labor That Doesn’t Get Accounted For

Few contractors struggle to explain where last month’s material spending went. But labor is a different story.

Material has a paper trail. Labor doesn’t, unless someone built one.

Plumbing companies bill T&M work at $45 to $75 an hour for a journeyman plumber, a rate that covers base wage, truck, tools, insurance and overhead [Angi, 2025].

When a technician spends 30 minutes each day on time that never gets written down or assigned to a specific job, those hours add up quickly. Across a full year, that’s more than 125 hours of untracked time per technician.

In a 10-technician operation, that’s over 1,250 unassigned labor hours every year. Hours that were paid but never connected to a client, a work order or a defined overhead bucket.

The consequences compound: the contractor closes the month with no way to know whether the margin shortfall came from pricing, a slow tech or labor that was never written down.

Service managers know which technicians stay busy. That’s not the same thing as knowing which technicians generate the strongest margins.

When margins tighten, pricing usually gets blamed first. In plenty of shops, the bigger issue is that 100 to 200 hours of labor per tech per year went somewhere, but nobody can say where.

Without those records, pricing, staffing and scheduling all get blamed equally.

Why Clients Push Back on T&M Invoices

Clients rarely question whether the work was completed. The disagreement starts with the hours surrounding it.

By the end of the day, the tech has a rough tally. The client got their repair. Neither wrote down when the tech arrived, how long the wait was, or how far he drove to get there.

TechBullion’s analysis of mechanical contractor billing data puts the dispute rate at 8% to 12% of invoiced hours [TechBullion, 2025]. That’s the direct hit. The indirect one is harder to measure: the time spent tracking down technicians, rebuilding timelines, waiting on payment.

According to Rabbet, 82% of contractors wait more than 30 days to get paid. Most plumbing contractors don’t lose a job because of one disputed invoice. They lose margin because nobody documented the supply-house run, the wait at the door or the extra trip across town.

How Verified Records Change the Conversation 

Ask the shops that rarely fight over invoices what they do differently. The answer is usually not a better contract or a tougher collections process. It's that someone logged what happened while it was still happening.

A disputed invoice is almost always a memory contest. The technician remembers the wait. The client remembers the repair. Without a record, neither side can prove anything, and the contractor absorbs the loss.

The president of a commercial punch-list contractor had a similar problem. They were “definitely underestimating time” but they “didn’t have the data to prove otherwise.” He concludes, “If I can’t predict how long it takes us to do something, we’re doomed to fail.”

Revenue is the easy part. Most shops can report what came in last month within minutes. But whether last month made money is a harder question. Most shops can’t answer it.

A cost and time tracking solution proved worthwhile for the owner of a property management maintenance operation. It allowed them to “present a complete bill to clients at the end of every 30 days with a full audit trail. Prior to having job-level time tracking, we didn’t have that supporting evidence.”

One Question for This Week

Take last month's total payroll hours and put them next to the hours that made it onto client invoices. Can you explain the difference?

If you can explain the difference, you're in good shape. If you can't, that's where the margin went.

Tracking this used to be painful. Paper timesheets, end-of-week memory, phone calls to reconstruct what happened three days ago. It placed a real burden on field crews and office staff alike, which is why most shops stopped trying. But the tools have caught up.

Today’s time tracking apps let techs log time against a job with a tap, capture location automatically, and close out a shift in under a minute. The barrier to building a reliable record is lower than it’s ever been.

The shops getting paid faster aren’t doing anything complicated. They’re just capturing what’s already happening, in real time, before anyone has a chance to forget it.

Most margin problems do not arrive all at once. They accumulate a few minutes at a time across hundreds of service calls and dozens of technicians.

For a 10-technician operation, recovering 30 minutes of unassigned labor per tech per day adds up to $56,250 to $93,750 annually. That’s 30 minutes times 250 working days times 10 techs at a loaded rate of $45 to $75 an hour. That’s 30 minutes times 250 working days times 10 techs at a fully loaded rate.

The labor was already paid for. But the invoice should say so.

Sources

1. Plumbers, Pipefitters, and Steamfitters (Bureau of Labor Statistics)

2. Plumbers, Pipefitters, and Steamfitters : Occupational Outlook Handbook (Bureau of Labor Statistics)

3. How Slow Payments Are Costing the Construction Industry Billions—and What You Can Do About It (rabbet.com)

4. Kathi Smith from Earned Run reviews Workyard (www.workyard.com)

5. Bill Kapaldo from Construction Punch Services reviews Workyard (www.workyard.com)

6. How Much Does Plumbing Repair Cost? (www.angi.com)