Construction businesses have more year-end complexity than most — job costing, subcontractors, equipment, WIP revenue recognition, and payroll that doesn't fit neatly into standard categories. The good news: if you get ahead of it in Q4, December 31 doesn't have to be a scramble. This guide covers the year-end accounting moves that matter most for construction companies and contractors in Washington state.
Why Construction Accounting Is Different
- Job costing is the foundation of sound construction accounting — every expense needs to be tied to a specific job. When job costing has been sloppy throughout the year, year-end is when that sloppiness becomes expensive
- Work in Progress (WIP) adds complexity: revenue recognition for in-progress projects requires an accurate WIP schedule before you can produce reliable year-end financials
- Subcontractor relationships create both administrative obligations (1099s) and legal exposure (worker classification risk)
- Equipment and depreciation decisions have real tax consequences — elections that significantly affect what you owe in April
Year-End Checklist for Construction Companies
- Equipment depreciation review — any equipment, tools, or vehicles placed in service this year should be reviewed for Section 179 or bonus depreciation elections. The key deadline is December 31
- Subcontractor 1099 prep — collect W-9s from every subcontractor you've paid $600 or more this year. 1099-NEC forms are due January 31. Start gathering now
- Job costing reconciliation — pull up your open jobs and review whether all costs are properly allocated. Catching problems before year-end lets you correct them while the details are fresh
- WIP schedule review — confirm your over/under billing calculations are current. Overbilling and underbilling affect both your financial statements and your tax position
- Payroll tax review — verify all payroll taxes have been properly remitted. Confirm year-to-date wages and withholdings are accurate before W-2 preparation begins
- Review accounts receivable — look hard at receivables. Genuine bad debt write-offs are deductible, but must be taken before year-end
- Equipment purchase timing — if new equipment is already in the plan for early next year, buying before December 31 pulls the deduction into this tax year
The Worker Classification Risk Every Contractor Needs to Understand
The IRS examines construction businesses closely when subcontractors make up a significant portion of the workforce. Calling someone a contractor doesn't make them one. Worker classification is determined by three factors: behavioral control (do you direct how the work is done?), financial control (do they work for other clients, bear business risk?), and the type of relationship (written contract, benefits, permanency).
If your subs work only for you, use your equipment, follow your schedule, and take direction from your foreman, the IRS may see employees — regardless of what your contracts say. The consequences of misclassification are serious: back payroll taxes, penalties, interest, and in some cases personal liability. Before year-end, take an honest look at how your subcontractor relationships are structured.
Key question: Do these individuals work for multiple contractors or primarily for you? Do they use their own equipment and bear their own business expenses? If you're uncertain, it's worth a conversation with an accountant before the IRS raises the question on their terms.
Q4 Tax Moves Specific to Construction
- Defer income where it makes sense — if you're on cash basis and have outstanding invoices for late-December work, invoicing in January shifts that income into 2027. Talk to your accountant before deciding
- Accelerate deductible expenses — outstanding vendor invoices, supply orders, tool purchases paid before December 31 become 2026 deductions
- Retirement contributions — SEP-IRA contributions can be made up to your filing deadline. Solo 401(k) plans must be established by December 31
- Vehicle mileage log — if you use a vehicle for business, your log needs to be current and complete. The IRS requires contemporaneous records
