Accounting for contractors: Construction accounting 101

Construction accounting is a specialized branch of financial record-keeping built to meet industry demands. Because construction companies operate through extended contracts that often involve multiple trades, changing scopes, and staggered payments, standard accounting methods simply don’t cut it.

Accounting in construction has to follow how jobs actually run. A contractor needs to see margin by job, not just at the company level. Plus, the numbers have to hold up against hours coded to the right job and cost code, retainage withheld on every draw, and labor burden allocated correctly across trades and classifications.

To learn more about accounting for contractors, read on. This guide explains the basics, how the process differs from traditional accounting, and how to set it up correctly.

What is construction accounting?

Construction accounting is built on project-based accounting principles, where every individual project receives its own cost structure, budget, and profitability analysis.

Contractors rely on construction project accounting to:

• Track profitability at the job level.
• Support accurate revenue recognition.
• Maintain clear cash flow visibility.
• Provide reliable financial reporting.
• Support informed operational decisions.
• Ensure compliance with industry standards and tax requirements.

Construction accounting matters because it supports financial control across active construction projects. Jobs can last for months or even years, so tracking finances only at the start or end of a project isn’t enough. Contractors need real-time visibility into how much they’re spending on things like labor, materials, and overhead. Otherwise, they’ll find issues like overtime spikes during short deadlines, unbilled change orders, and missed material purchases after it’s too late to address them.

Construction accounting vs. traditional accounting

Accounting in the construction industry is unique because of the project-based nature of construction work and the structure of contracts.

Here’s how construction accounting differs from standard methods:

How to do construction accounting: 5 steps

The five steps below outline the core mechanics that firms need to set up construction accounting correctly from end to end. These foundations support accurate reporting, steady cash flow, and reliable insights for leadership.

1. Track costs by job using a job costing system.

Effective construction accounting starts with a structured job costing system. This process ties direct costs (labor, subcontractors, materials, equipment) and indirect costs (insurance and overhead) to specific projects. 

Job costing depends on timely, accurate cost capture. Payroll hours, material purchases, and subcontractor invoices should post directly to jobs and cost codes. Accounting software needs to support job-level reporting without the need for manual workarounds.

2. Choose and apply the right revenue recognition method.

Revenue recognition means accounting teams record income when it’s earned, not when the cash is received. In construction, contractors typically track revenue using the percentage-of-completion method, which lays out how much they’ve earned based on the amount of work done. 

If the project and business qualifies, contractors can also use the completed-contract method, which defers revenue until project completion. The One Big Beautiful Bill Act (OBBBA) changed the eligibility requirements for this method. Now, contracts must fall into one of two categories: 

• Smaller businesses and projects: Construction companies need to average $31 million or less in gross receipts for the previous three years. And the project must be completed within three years.
• Residential projects: Contractors working on single and multi-family units qualify if at least 80% of their total estimated costs go toward building or restoring the property

3. Set up a construction-specific billing process.

Contractors submit pay applications to owners when work is complete. This document is essentially an invoice that outlines more construction-specific details. 

One important part is the payment application form, such as AIA G702 or G703. The form lists all the financial information, including the total of the work completed. This figure is based on the schedule of values, which outlines the cost of each task required to complete the project. Before submitting the final bill, contractors need to subtract their retainage withholding, often 5–10%. 

Using this system means contractors and subcontractors aren’t waiting until the end of the project to get paid, and clients aren’t responsible for a hefty bill all at once.

4. Run multi-job, multi-state, and certified payroll.

Each pay run must allocate labor hours to the correct projects and cost codes while applying the right state and local tax rules. Public works jobs add another layer, requiring weekly certified payroll reports on prevailing wage calculations and fringe benefits by trade and classification.

Some contractors do this by hand, and others use generic software that isn’t designed for the complexities of construction payroll. Both options increase the likelihood of mistakes. Manual payroll runs lead to math errors and duplicate entry, and general accounting platforms don’t always have the built-in ability to segment expenses by job. Construction-specific payroll solutions address these issues and more, making accurate accounting simpler.

5. Close the books at the project and company level on a regular cadence.

Close the books on a regular basis; many contractors do so monthly. Closes should include job-level reviews, WIP updates, and reconciliation between job costs and the general ledger. Ideally, project managers should review profit and loss (P&L) reports during each close cycle. They’ll look for unbilled change orders or labor overruns to ensure each expense is coded correctly and see whether these costs threaten profit margins.

9 construction accounting best practices

The following best practices support accuracy and visibility across construction projects:

• 1. Use specialized construction accounting software: Construction accounting software supports job costing, WIP reporting, and retainage tracking better than general accounting software.
• 2. Capture committed costs, not just actuals: Open purchase orders, subcontractor commitments, and approved change orders should appear in job forecasts to reflect true cost-to-complete.
• 3. Reconcile WIP monthly and review results with operations: Monthly WIP reviews identify over and under-billings early and keep revenue recognition aligned with the reality on the jobsite.
• 4. Use one cost code structure everywhere: Using a shared cost code structure across estimates, payroll, and the field improves data accuracy.
• 5. Post labor and payroll data to jobs frequently: Daily or weekly payroll feeds improve job cost accuracy and cash flow visibility, supporting better project-level decision-making.
• 6. Track labor burden accurately by job: Base taxes, insurance, and fringe benefits on job-specific labor activity rather than company-level averages.
• 7. Add signed change orders to the cost ledger immediately: Prompt updates keep job budgets and margin reports accurate.
• 8. Run job-level P&L for all active projects: Regular job P&L reviews surface risks early, preventing surprises at close-out.
• 9. Stay current on accounting standards and payroll compliance rules: Ongoing attention to revenue recognition guidance and certified payroll requirements reduces audit and compliance risks.

Common construction accounting mistakes

Even experienced contractors make mistakes in construction accounting, which can distort job costing, weaken cash flow control, and lead to compliance risks across projects.

Here are some of the most common issues to watch out for:

• Job costs and general ledgers that live in silos: When job cost data and the GL don’t flow into one another, the numbers drift apart and financial reporting stops being accurate.
• Using the wrong level of cost-code detail: Overly broad codes hide problems, while excessive detail leads to inconsistent coding.
• Ignoring committed costs in forecasts: Budgets that exclude purchase orders and subcontractors understate the true cost-to-complete.
• Letting WIP drift between closes: Unreconciled WIP schedules distort revenue recognition and margin visibility.
• Applying the wrong revenue recognition method: An incorrect completion method can lead to misstated revenue, inviting audit issues.
• Failing to record signed change orders promptly: Delays cause inaccurate job costing and unexpected margin erosion.
• Allocating labor burden inconsistently: Incorrect payroll and burden allocations hide real labor costs and damage profitability.

Improve construction accounting with Miter.

Construction accounting relies on efficiency and precision. Problems arise when labor and spend data shows up late or coded wrong. Many contractors still track time, payroll, and expenses data in separate, disconnected systems. This leads to inaccurate job costing and unclear cash flow reporting.

Miter fixes these issues. Payroll and Time Tracking send labor and burden directly to the right jobs and cost codes. Spend tools capture card purchases, reimbursements, and bills at the moment they occur and assign them to the right construction projects immediately. Seamless integrations with accounting tools like Sage, Viewpoint, and QuickBooks keep the general ledger up to date without the need for extra cleanup. 

The result? Month-end closes run faster, and accounting workflows stay simple and practical. With Miter Integrations, Job Costing, and Expense Management, finance leaders get clear, reliable numbers without changing their accounting software.