How to Get Every Worked Hour Onto the Invoice on T&M Electrical Jobs
You have your rates right. Your T&M agreements are signed. You bill weekly, maybe biweekly. On paper, everything checks out.
But a T&M invoice only bills the hours somebody wrote down. Setup, drive time, a quick favor for the GC, a change order handled on the spot: these are the hours that slip between the job site and the invoice, and when they do show up as a bare number, they are the hours a customer can't check.
This post is about diagnosing exactly where those hours go. If you want a full walkthrough of T&M billing processes, read our T&M billing best practices guide. This article is about where hours still slip even when you follow those practices.
Where Do T&M Hours Disappear?
Billable hours vanish at the edges of the workday -- arrival setup, drive time, quick favors, change orders, and end-of-day cleanup that nobody logs.
The First 15 Minutes
Your crew pulls up to the site at 7:00 AM. They unload the truck, haul gear inside, check the plans, set up the work area. Nobody clocks in until 7:15 because they are not "working" yet.
Fifteen minutes does not sound like much. Multiply it by 10 workers, both ends of the day, five days a week. That is 25 hours per week of on-site time that never hits a timesheet.
Example arithmetic: at an $85/hour T&M billing rate, 25 hours is $2,125 a week, if your contract makes setup billable. Run it with your own crew and rate.
Drive Time Ambiguity
Your contract says "portal to portal." That means the clock starts when your worker leaves the shop. But your crew does not log travel separately -- they clock in when they arrive on site.
A 30-minute drive each way is an hour of billable time per worker per day that your contract entitles you to but your timesheets do not capture.
The Quick Fix Trap
The GC walks over. "Hey, can you guys just look at this outlet in the break room? It's been flickering."
Your journeyman spends 20 minutes diagnosing a loose neutral. Nobody writes it down. It was not part of the scope. It was not a change order. It was just a favor -- and on an active T&M job it can happen several times a week.
Change Orders Without Time Tracking
The owner wants an extra circuit in the conference room. Your foreman says sure, writes it on the daily log. The materials get tracked. The labor does not.
Three hours of journeyman time on that change order disappears into the general bucket of "hours worked today." When the invoice goes out, those hours are buried in the total instead of billed as extra scope.
End-of-Day Cleanup
The last 15-20 minutes of every day -- sweeping up wire scraps, coiling cords, securing the panel, locking the gang box. It is real work. It is required by the GC. And on most crews, it happens after the last clock-out.
How Many Hours Could Be Slipping? A Worked Example
The arithmetic below uses one example crew: 10 workers, 30 minutes of unrecorded billable time per worker per day, $85/hour. These are example inputs, not a claim about your shop.
Here is the math, line by line.
10 workers x 30 minutes/day = 5 hours/day of missed billable time.
5 hours/day x 5 days/week = 25 hours/week.
25 hours/week x 50 weeks/year = 1,250 hours/year.
1,250 hours x $85/hour billing rate = $106,250/year.
Your number depends on your crew size, your rate, and how many minutes actually slip. Use our revenue leakage calculator to run it with your own inputs, and time a real week before you trust any estimate.
Why Does This Keep Happening Even With Time Tracking?
Most contractors already have a time tracking process. It still fails because the capture happens too late, categories are too broad, and nobody reviews until the data is stale.
Clock-In Friction
If your app takes 30 seconds to load, or the worker has to scroll through a list of jobs, or there is no cell signal in the parking garage, the clock-in happens five minutes late. Every day. On every worker. That friction is small enough that nobody complains, and expensive enough that it adds up to thousands.
Everything in One Bucket
When all hours go under a single "labor" category, you cannot distinguish T&M work from fixed-bid work. You cannot separate drive time from on-site labor. You cannot identify which hours belong to a change order and which are base scope.
Without categories, your time data is just a number. It is not information you can bill against.
Review Comes Too Late
Most contractors review time entries at payroll -- once a week or once every two weeks. By then, the details are gone. Was Thursday's 9.5 hours on the T&M job or the fixed-bid job across the street? Nobody remembers. So it gets split evenly, and the T&M invoice comes up short.
The QuickBooks Gap
Your crew logs time in one system. Your invoices live in QuickBooks. Someone has to manually transfer the data. That transfer step is where hours get rounded, categories get dropped, and line items get missed.
Every manual step between clock-out and invoice is an opportunity for revenue to disappear. A direct QuickBooks sync that pushes TimeActivity records with one click removes the re-keying step.
The 5 Fixes That Actually Recover T&M Revenue
These are not best practices. These are specific changes to your workflow that put dollars back on your invoice.
Fix 1: Redefine Clock-In as Arrival, Not Work Start
Your crew should clock in when they arrive on site, not when they pick up their first tool. If the contract says portal to portal, the clock starts when they leave the shop.
Put it in writing. Add it to your T&M agreement: "Billable time begins at site arrival and ends at site departure, including setup and cleanup."
Then enforce it. If your time tracking tool makes it easy to clock in with one tap from a phone, compliance goes up because there is no reason to delay.
Fix 2: Separate T&M Hours from Everything Else
Create distinct job categories for T&M work, fixed-bid work, change orders, travel, and non-billable time. Every clock-in should require selecting the right category.
This is not overhead. It is revenue. When a journeyman logs three hours under "T&M - Johnson Office" instead of just "Johnson Office," that time can be billed at the T&M rate with full documentation. When it all goes in one bucket, the T&M hours get diluted or lost.
Fix 3: Capture in Real Time, Not at End of Day
End-of-day timesheets are memory exercises, and on T&M work an hour that gets remembered short comes directly off your invoice.
Real-time mobile clock-in captures the actual start and stop. No rounding. No guessing. No Friday afternoon reconstructions from memory.The difference between real-time capture and end-of-day recall is the difference between billing 7.75 hours and billing 8.25 hours. Over a year, across a crew, run that half-hour gap at your own rate.
Fix 4: Bill Weekly, Not Monthly
Monthly billing on T&M work is a trap. Four weeks of accumulated hours are harder to verify, easier to dispute, and more likely to contain errors that you eat instead of correcting.
Weekly invoicing forces a weekly review. You catch missing hours while the crew still remembers Tuesday. Customers approve charges while the work is fresh. Payment starts sooner because each invoice goes out sooner.
For a detailed billing cadence framework, see our T&M billing best practices guide.
Fix 5: Automate the Path from Timesheet to Invoice
Every manual step between time capture and QuickBooks invoice is a leak. Data entry errors. Forgotten line items. Categories that get flattened during transfer.
A direct QuickBooks sync creates TimeActivity records from your time entries when an admin clicks sync. No re-keying. No CSV exports. No Friday night data entry sessions.
The goal is zero manual steps between clock-out and invoice line item. Every step you remove recovers revenue.
The Compounding Effect of Better T&M Capture
Recovering lost T&M hours does more than fix this month's invoice. Better time data compounds across your entire business through more accurate bids and healthier margins.
When you capture accurate hours on T&M jobs, your job costing gets honest. You see which jobs actually run 15% profit and which ones are barely breaking even. That data feeds your next round of estimates -- the same feedback loop described in our job costing guide for electricians.
Contractors who bid based on accurate historical data stop underbidding. They stop winning jobs that lose money. They start winning jobs at rates that reflect what the work actually costs. For a step-by-step system design, see our complete time tracking guide for electrical contractors.
The same leak shows up in margin: hours given away on T&M work come straight off the margin you thought you bid, and the bids built on those numbers inherit the error.
Every recovered hour is work that was already performed and can now be billed, with a description the customer can check. The Thursday overtime surprise stops being a surprise when you can see the hours in real time.
Frequently Asked Questions
What counts as billable time on a T&M electrical job?
Billable time includes all hours the contractor spends on the project as defined in the T&M agreement. This typically covers on-site labor, travel (portal to portal), setup and cleanup, material procurement trips, and time waiting for site access. The key is defining it in the contract before work begins. If it is not written down, it will get disputed.
How do I track change order hours separately from base T&M scope?
Create a separate job code or time category for each change order. When a worker starts change order work, they clock into that specific category -- not the general T&M bucket. This gives you a clean line item on the invoice and documentation if the customer questions the charge.
What is the biggest source of unbilled hours on T&M electrical work?
Setup and cleanup time at the beginning and end of each day is a common one, because it happens every day and nobody writes it down. In the worked example above, 30 minutes per worker per day on a 10-person crew at $85/hour comes to $106,250 a year; run it with your own numbers.
How often should I invoice on T&M jobs?
Weekly. Monthly billing increases the chance of disputed hours, forgotten details, and cash flow gaps. Weekly invoicing keeps charges fresh in the customer's mind, forces a weekly time review that catches missing hours, and starts your payment cycle sooner. See our T&M billing best practices for a complete billing cadence framework.
How do I handle a customer who disputes T&M hours?
Documentation and frequency. Detailed daily logs with work descriptions, worker names, and hours per task make disputes resolvable. Weekly billing keeps charges small enough that customers review and approve them promptly. The contractors who get pushback on T&M hours are almost always the ones billing monthly with minimal documentation.
Can I recover T&M revenue I have already lost?
You cannot bill retroactively for hours you did not capture. But you can start capturing them this week. The five fixes in this article (redefining clock-in, separating categories, real-time capture, weekly billing, and automated sync) can be implemented incrementally.
Your crew is already working the hours. FieldTimesheet makes sure those hours reach the invoice. One-tap clock-in, a note on every entry, and a one-click QuickBooks sync close the gap between time worked and time billed. Start your free 14-day trial and see what your crew's hours look like with a note on every entry.