QuickBooks Cleanup for Small Businesses: 7 Signs Your Books Need a Reset

For contractors, a full schedule does not always mean a profitable business. 

A remodeler can have crews booked for months. A plumber can keep adding jobs. A specialty contractor can watch revenue climb all year and still finish projects with far less profit than expected. The problem is rarely the volume of work. It is not knowing what each job actually costs while the work is still in progress. 

The margins leave little room for error. According to NAHB’s Remodelers’ Cost of Doing Business Study, residential remodelers averaged a 29.9 percent gross profit margin in 2024 but only a 6.3 percent net margin after overhead. One job that runs a few thousand dollars past estimate can erase the profit on the job beside it. 

Job costing for contractors closes that blind spot. Around Greenville, where construction and remodeling demand has stayed strong along corridors like Woodruff Road, that visibility matters more as job volume grows. 

What Is Job Costing for Contractors? 

Job costing measures the financial performance of each individual project. Instead of asking whether the company made money this month, you ask whether this particular remodel, plumbing job, or painting contract made money. 

That distinction matters. A contractor can finish the year with respectable revenue and still find that several projects produced almost no profit. One job needed more labor than estimated. Another absorbed unexpected material costs. A third only looked profitable because equipment or subcontractor costs were never assigned to it. 

QuickBooks describes construction job costing as tracking project-specific costs such as labor, materials, equipment, and overhead to determine the total cost of a job. 

Why Revenue Does Not Tell You Whether a Job Was Profitable 

A $100,000 project sounds better than a $70,000 project. Revenue alone tells you almost nothing about profitability. 

Project A brought in more revenue and less profit. Bigger contracts also carry bigger labor overruns, more subcontractor exposure, and longer timelines for costs to drift. Construction bookkeeping only answers these questions when transactions are assigned to the jobs that produced them. 

Which Costs Should Contractors Track by Job? 

• Labor: Usually, the largest and most underestimated cost. Track hours by job, and use a rate that reflects payroll taxes, benefits, and insurance rather than the wage on the timesheet. 
  
• Materials: Assign lumber, drywall, paint, fixtures, plumbing supplies, flooring, and consumables to the project where they were used. A run of $150 and $300 supply purchases can quietly move the margin on a long job. 
  

• Subcontractors: Electrical, plumbing, HVAC, drywall, roofing, and landscaping work should be tied to the relevant project. Recorded as one general expense, you know what was spent but not which job spent it. 
  

• Equipment and project expenses: Equipment, dumpster fees, permits, delivery charges, and site preparation. A useful rule: if the cost would not have happened without that project, it belongs in that project’s cost record. 

What About Overhead? 

Direct costs are straightforward. Overhead is harder because it supports the whole business: office rent, administrative salaries, insurance, software, vehicles, marketing, and accounting fees. 

A project can look highly profitable when the report compares revenue only with labor and materials, but that gross profit still has to cover overhead. There is no single allocation method that fits every contractor. Some use labor hours, some labor cost, and some project revenue. What matters is applying the same method every time. 

Estimated Costs vs. Actual Costs 

The most valuable job costing report compares what you expected a project to cost with what it actually cost. 

This project ran $9,500 over estimate. The variance matters more than the final number, because it prompts the right questions. Was the labor estimate too low? Did the scope change? Did crews spend unrecorded time correcting mistakes? Did material prices rise? The lesson from one finished project should improve the next bid. 

Common Job Costing Mistakes Contractors Make 

• Combining multiple jobs under one customer: Create a separate job for each project so income and expenses stay separate. 
• Tracking materials but not labor: Receipts are easy. Labor needs disciplined time tracking, and ignoring it makes jobs look more profitable than they were. 
• Missing change orders: The added labor and materials get recorded, the additional revenue never gets billed, and margin disappears quietly.
• Recording expenses without assigning them to a project: The books are complete but useless for management decisions. 
• Reviewing job costs only after completion: On longer projects, compare estimated and actual costs while the work is underway so overruns can still be addressed. 

Making Job Costing Work in Your Accounting System 

Most project-based businesses handle this inside their accounting software. QuickBooks, for example, offers job costing features that track materials, labor, and vendor costs by project. Capabilities vary by product and subscription. 

The software does not create accurate job costing on its own. The reports are only as good as the inputs: separate jobs, correct expense codes, time assigned to projects, and reconciled accounts. Get those wrong and the dashboard looks polished while giving the wrong answer. 

Which Numbers Should Contractors Review? 

• Estimated vs. actual cost, to see whether the job is holding to its assumptions 
• Gross profit, or revenue minus the direct costs assigned to the project 
• Gross margin percentage, which makes different-sized jobs comparable 
• Labor variance, comparing expected hours or cost with actual usage 
• Material variance, and the reason purchases exceeded the estimate 
• Change order performance: documented, priced, approved, and billed 

Over time, these numbers reveal patterns. Bathroom remodels may consistently perform well while additions run over. One estimator may be consistently optimistic about duration. That is the information that shapes better bids. 

Know Which Jobs Are Actually Making You Money 

Being busy is not the same as being profitable. When labor runs past estimate, materials get coded to the wrong project, change orders go unbilled, or subcontractor costs sit in a general expense bucket, a job can look successful right up until the final numbers say otherwise. Job costing for contractors closes that gap by measuring each project’s revenue against the costs it actually consumed, so profitable work can be repeated and the next bid is priced on real data. 

Small Business Services LLC has spent years keeping the books for construction companies, remodelers, plumbers, painters, and specialty trades across Greenville and the Upstate. Its bookkeeping services keep project-level records accurate and current, giving contractors the clean cost data that reliable job costing depends on.  

Ready to stop chasing invoices and start getting paid on schedule? Call +1 (864) 905-8081 or email roby@sbsofsc.com today.