Start by creating consistent cost categories that match how you bid work. Most contractors need at least three buckets per project: labor, materials, and subcontractors. Depending on your trade, you might also break out equipment rentals, permits, and project-specific overhead. The categories should mirror your estimates so you can compare what you quoted to what you actually spent.

Every expense needs to be assigned to a specific project. When you buy materials at Home Depot, that receipt gets coded to the job it’s for. When a sub sends an invoice, it goes to the project they worked on. When your crew logs hours, those hours get allocated to the right job. If expenses end up in a general bucket with no project attached, your job costing falls apart and your financial reports become useless for decision-making.

Labor tracking is where most contractors struggle. Your crew might work on two or three jobs in a single week. You need a way to capture how many hours went to each project. Time tracking apps work well for this. Even a simple spreadsheet is better than guessing at the end of the month. Labor is often 30% to 50% of project cost, so getting this wrong means your project margins are fiction.

Subcontractor costs need the same attention. If you’re a general contractor or remodeler using multiple subs, each invoice should be tied to the correct job before you pay it. Subs can represent half or more of your total project cost. Lumping them into one account without project detail defeats the purpose of tracking anything by project in the first place.

Track committed costs, not just what you’ve already paid. If you’ve signed a contract with a plumber for $12,000 but only received $4,000 in invoices so far, your actual cost exposure on that project is $12,000. Looking only at paid invoices gives you a false sense of where you stand mid-project.

Compare your budget to actual costs regularly. Weekly during active projects is ideal. Monthly is the minimum. If you wait until the job is done to look at the numbers, you’ve lost the chance to make adjustments. A simple report showing estimated cost versus actual cost plus remaining commitments tells you whether you’re on track or heading toward a loss.

QuickBooks Online handles this well when it’s set up correctly using the Projects feature. You can tag income and expenses to specific jobs and pull profitability reports per project. The key is configuring it properly from the start and being disciplined about coding every transaction. Most contractors we work with in the Tampa Bay area already have QuickBooks but aren’t using the project tracking features, which means they have the tool but not the insight.

The goal is knowing your real profit on every project. That information changes how you bid future work, which subs you use, and where your crew’s time goes. Without it, you’re running your business on gut feeling. With it, you’re making decisions based on actual data. If you’re behind on getting this organized, having a professional handle your small business bookkeeping with proper job coding from the start saves you from trying to reconstruct project costs after the fact.