Every expense needs to be assigned to a specific job at the time it happens. This is the foundation of tracking project costs. Buy materials at the supply house? Code it to that project right then, not weeks later when you can’t remember which job it was for. Wait too long and you’ll either code it wrong or dump it into general expenses where it tells you nothing.

Start by setting up cost codes that match how you estimate projects. Most contractors break jobs into phases like site work, foundation, framing, rough-ins, finishes, and punch list. Within each phase, separate labor, materials, and subcontractor costs. This structure lets you compare actual costs to your estimate at a level detailed enough to spot problems before they blow up your margin.

Use your accounting software’s job costing features properly. QuickBooks handles this well if configured correctly. When you enter an expense, assign it to the specific project and phase where it belongs. Don’t just categorize something as “materials.” Assign it to “framing materials for Smith project.” That job-level detail is what shows you profitability by project instead of just overall company numbers.

Labor tracking matters as much as material tracking. If your crew works on multiple jobs in a day, their hours need to be split between those projects. Use simple time tracking apps or even paper timesheets, but make sure hours get recorded daily and assigned to the correct job. Guessing at labor allocation after the fact makes your job costing data useless.

Subcontractor invoices often represent 40 to 60 percent of a project’s cost. Every sub invoice needs to be coded to the right job before you pay it. If those invoices just hit a general subcontractor expense account, you have no idea which projects are actually profitable.

Take photos of receipts with your phone and save them digitally. Apps like Dext or Hubdoc can pull receipts directly into your accounting software. Paper receipts fade, get lost in the truck, or become illegible after a few months. Digital copies organized by job are searchable and survive audits.

Compare budget to actual weekly during active construction. Monthly reviews mean you find out about the framing overrun after the house is dried in. Weekly reviews let you catch problems while you can still make adjustments. Build a simple report showing budgeted cost by phase versus actual cost to date.

Don’t forget committed costs. You’ve signed a $30,000 contract with an HVAC sub but only received $10,000 in invoices so far. Your spent-to-date looks fine. Your actual position is that you’re already over budget on mechanicals once the remaining invoices arrive. Track what you’ve committed, not just what you’ve paid.

The system doesn’t need to be complicated. It needs to be consistent. Track every expense as it happens, code it to the right job and phase, save the receipt, and review weekly. Do that and your books will actually show which projects made money and which ones lost it.

Most contractors who complain about not knowing their real margins aren’t tracking costs properly. If tracking feels overwhelming, a contractor bookkeeper in American Fork can set up systems that make it manageable and catch errors you’d miss doing it yourself. The discipline required is more than most contractors have time for while running jobs, but the payoff is knowing exactly where your money goes and where your profit actually comes from.