Guide · Construction

Accounting for construction companies – job costing, WIP, and AIA billing.

Construction accounting is operationally intensive and structurally different from general business accounting. Job costing, WIP schedules, percentage-of-completion revenue recognition, AIA billing, retainage, lien waivers – each has specific mechanics. This guide covers what construction accounting actually requires.

Job costing

Job costing: the foundation of construction accounting

Every construction accounting decision traces back to job costing. Generic bookkeeping treats a construction company's expenses as firm-wide overhead; construction accounting assigns every dollar of cost to a specific job. The difference is the difference between useful construction P&L and useless noise.

Chart of accounts structure

Construction chart of accounts has two dimensions beyond standard:

  • Job/project. Each project gets its own job number tracked as class, dimension, or project code.
  • Cost code. Within each job, costs categorize into cost codes (labor, materials, subcontractors, equipment, other direct costs, overhead allocation).

Combination produces job-level cost tracking: Job 2026-14 – Labor – Carpentry – $24,500. This granularity enables: cost-vs-budget variance per job, margin analysis per job, contractor performance analysis.

Platform requirements

  • Sage 300 CRE (Timberline) – dominant in mid-market commercial construction
  • Foundation Software – small-to-mid contractor focus
  • Viewpoint Vista/Spectrum – mid-market and enterprise
  • Procore Financials – project management-integrated
  • ComputerEase – small contractor focus
  • QuickBooks Contractor – very small contractors only; hits scalability ceiling quickly

Generic QBO works for contractors under $2M annual revenue with simple jobs. Beyond that, construction-specific software is almost always warranted.

Revenue recognition

WIP and percentage-of-completion

Construction revenue recognition under ASC 606 typically uses percentage-of-completion (POC) for long-term contracts. Alternative: completed-contract method for short-duration contracts.

Percentage of completion mechanics

POC recognizes revenue based on project completion percentage, typically measured as cost-to-cost: costs incurred / total estimated costs = % complete. So a project where $280k of $700k total estimated costs have been incurred is 40% complete, triggering recognition of 40% of contract revenue.

WIP schedule

The WIP schedule is the construction controller's primary monthly deliverable. For each active project, it shows contract value (original + approved change orders), estimated total cost, estimated gross profit, costs incurred to date, percentage complete, revenue earned to date, billed to date, and overbilling / underbilling.

Overbillings and underbillings

Overbillings (billings exceeding earned revenue) are liabilities – contractor has been paid for work not yet completed. Underbillings (earned revenue exceeding billings) are assets – work completed but not yet billable. Bank and surety review both for risk assessment.

Surety bonding requirement: contractors pursuing bonded work have surety companies requiring monthly or quarterly WIP schedules in specific formats. Incomplete or inconsistent WIP reporting causes bonding capacity issues. Surety-ready WIP is a specific competency; construction-trained offshore accountants know the format requirements for major sureties.
AIA billing

AIA billing, retainage, and payment mechanics

AIA billing

AIA Document G702/G703 is the standard commercial construction billing format. Each month, contractor submits Application for Payment showing scheduled value per line item, work completed this period, total work completed to date, materials stored, retainage, and current amount due.

AIA billing has conventions that generic bookkeeping doesn't handle: specific line item breakdowns must match the schedule of values agreed in the contract; changes require change order approval before billing; architect/engineer approval required before owner pays.

Retainage

Retainage is a percentage of each billing withheld by the owner until project completion. Typical: 10% retainage on first 50% of contract, sometimes reducing to 5% thereafter. Released at substantial completion or final completion.

Accounting: retained amounts sit as AR but not immediately collectible. Aging requires separate tracking. Most contractors show retainage receivables as a separate AR subcategory.

Lien waivers

Before paying contractors and subcontractors, owners typically require lien waivers – signed documents waiving mechanic's lien rights on amounts paid. Accounting tracks lien waivers alongside payments to document protection status.

Pay-when-paid vs pay-if-paid

Contractor payment to subs often tied to contractor's own payment from owner. Pay-when-paid: sub gets paid when contractor gets paid (valid but timing-based). Pay-if-paid: sub only gets paid IF contractor gets paid (creates real risk transfer; enforceability varies by state).

Monthly reporting

Monthly reporting contractors actually use

  • WIP schedule. Every active project, monthly. Essential for internal management + bank + surety.
  • Project-level P&L. Revenue, direct costs, gross profit, % complete – per project.
  • Overhead cost allocation. Indirect overhead allocated to projects using predetermined overhead rates.
  • Backlog report. Contracts signed but not yet started or not yet completed; future revenue visibility.
  • Cash flow projection. Construction cash flow is lumpy; projecting 13 weeks forward reveals crunches.
  • Change order log. Change orders pending approval, approved, in dispute; revenue impact tracking.
  • AR aging with retainage separated. Current AR vs retainage receivable shown separately.
  • Subcontractor payment status. Who's been paid, who's waiting, lien waivers received.
  • Equipment utilization. For contractors owning equipment, cost per operating hour and utilization rate.
  • Labor productivity. Estimated hours vs actual hours by cost code.

Related: construction industry page, construction case study, offshore bookkeeping.

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