Job Costing for Contractors: A Simple System for Solo and Small Operators
Search "job costing for contractors" and almost everything you find assumes you have an office, a bookkeeper, and a crew on payroll. That is not most contractors. Most contractors are one or two people, one or two vans, quoting work in the morning and buying materials in the afternoon. This guide is the simple version of job costing for that contractor: what it is, why skipping it quietly costs you money, and how to do it without becoming a bookkeeper.
Why Contractors Lose Money Without Job Costing
You can be busy, well booked, and good at the work, and still not know which jobs actually make money. That is the trap. Without job costing, your only feedback is the bank balance at month end, and a healthy balance hides the losers. One job that came in over on materials and took three extra visits gets covered by a good job the week before, and you never learn that your quote on that type of work is wrong.
The cost of not knowing is not one bad job. It is quoting the next ten the same way.
What Job Costing Means for a Small Operator
Job costing is simply tracking every cost that belongs to one job, then setting it against what you charged, so you can see the profit on that job by itself.
You do not need the version the big guides push, with labour-burden rates and overhead absorption formulas. For a solo or small operator, the honest version is: count what the job cost you, including your own time, and subtract it from the price. That is enough to run your business on.
The Tracking Methods That Fail
Three methods are common, and all three leak:
- Memory. You tell yourself you will remember what the job cost. You will not. The second parts run and the £8 parking are gone by Friday.
- The bank statement. It shows money in and money out, but not which job each cost belonged to, so it can never give you profit per job.
- The spreadsheet. Better, but it only holds what you type in, and it lives on a laptop at home while the costs happen in a merchant car park. The gap between the two is where the missing costs live.
A Practical Receipt-First System
The system that actually holds up is built on the one thing every job cost already comes with: a receipt. Capture the receipt the moment you get it, tag it to the job, and the costing does itself.
- Capture at the counter. Scan every receipt when it is in your hand, not at the weekend. That is the one moment you will never forget which job it was for.
- Tag it to the job. Tell the app which job the cost belongs to. VanReceipts uses the time and place of the receipt to suggest the right job, so it is usually one tap.
- Add your labour and subs. Log your hours at your rate, and anyone you paid, so the total is the whole cost, not just the parts with a slip.
- Read the profit. With costs tagged and labour logged, the profit on each job is already there. No month-end write-up.
The full method, step by step, is in how to track job costs from receipts.
The Costs to Track
| Cost | Why contractors miss it |
|---|---|
| Materials | The second and third supply runs, never added up |
| Subcontractors and hired help | Cash payments with no receipt |
| Plant and tool hire | Treated as general cost, not costed to the job |
| Skip hire and disposal | Forgotten until the invoice lands |
| Mileage | Trips to the merchant and site, never logged |
| Your own labour | Left out entirely, so every job looks profitable |
The rule of thumb: if it cost you money to do the job, it belongs to the job. The small ones are the ones that quietly thin a margin, and they are exactly what a spreadsheet never captures.
Your Own Time Is a Real Cost
The most common contractor mistake is leaving your own labour out of the maths. If you only count materials and cash paid to others, every job looks like it made money, because you worked for free in the calculation. Put a rate on your hour, whatever you would pay someone to do your work, and count your hours on every job at that rate. A job that "made good money on materials" but ate three days looks very different once your time is in, and correctly so.
A Worked Example
Take a job you quoted at £3,000.
- Materials, across four supply runs: £780
- Your labour: 26 hours at £38 an hour: £988
- A subbie for two days: £360
- Skip hire: £220
- Mileage, supply and site trips: roughly £40
- Job overhead allocation: £120
Total cost: £2,508. Profit: £492, about 16 percent. Solid, but the skip and the fourth supply run were what kept it from being better, and neither would have shown up in a materials-only glance at the bank. Next time you quote similar work, you build both in.
Run your own numbers with the free job profit calculator.
How It Sharpens Your Bids
Cost a handful of jobs properly and the patterns arrive quickly. You learn which types of work actually clear a margin and which barely break even, where your quotes are consistently short (usually your own time and the trips back), and which customers or job types are worth chasing. That evidence beats any pricing guide, because it is your suppliers, your area, and your way of working.
US and UK Tax Notes
Every cost you track for job costing is also a deductible business expense, so the habit does two jobs at once. In the US, that means clean records for your Schedule C. In the UK, sole traders report the same expenses on Self Assessment, and anyone working under the Construction Industry Scheme needs tidy records of materials versus labour. Capture receipts as you go and the figures are ready when the return is due.
What VanReceipts Does for Contractors
VanReceipts is built for the one-van contractor: estimates and invoices on the job, scan every receipt from the front seat (totals and line items on your phone), log mileage and hours, and live profit for each job is there without a spreadsheet. Because it suggests the right job from the time and place of the receipt, keeping several jobs straight in a busy week is a tap, not a puzzle.
Start with the complete guide to job costing, and see the trade-specific versions for electricians, plumbers, and HVAC techs.
FAQ
What is job costing for contractors?
It is tracking every cost on a single job, materials, subcontractors, hire, mileage, and your own labour, then subtracting that total from what you charged, so you can see the profit on each job rather than just your overall bank balance.
Do I need accounting software to do job costing as a contractor?
No. A spreadsheet works, and a receipt-scanning app that tags each cost to a job works better because it captures costs as they happen and calculates per-job profit for you. You only need something that keeps every cost attached to the right job.
How do I account for subcontractors in job costing?
Log every payment to a subbie or hired hand against the job they worked on, whether you have an invoice or paid cash. Subcontractor cost is one of the biggest line items on many contractor jobs, so leaving it out makes a job look far more profitable than it was.
Should a solo contractor use the same job costing as a big firm?
No. The full version with labour-burden rates and overhead absorption is built for firms with payroll and an office. A solo or small operator only needs to count real costs, including their own time, against the price. Keep it simple enough that you actually do it.
Starting on Your Next Job
You do not need to cost every job you have ever done. Start with the next one: scan every receipt, log your hours, and add it up when the job closes. The first time you see real profit per job instead of a guess, you will not want to quote any other way.
Download VanReceipts on the App Store and cost your next job from the front seat of the van.