Most tax prep checklists were written for retail businesses or service firms. They tell you to gather your bank statements and leave you to work out the rest, which is how construction owners end up handing their CPA a box of receipts and hoping. This guide covers what a construction-experienced CPA actually needs: WIP schedule, retainage receivable, job-level profit and loss, financed asset reconciliation, 1099-NEC lists, mileage logs, and the rest of what generic checklists miss.
Contractors across the country do the same thing. They hand their CPA a box of receipts, an accounting file that has not been reconciled since October, and a list of jobs the CPA has never heard of. The CPA spends three billable hours on bookkeeping before starting the return. The return comes back late, over budget, and often leaves real deductions unclaimed, because the CPA never had the data to find them.
None of that is a tax problem. It is a bookkeeping problem that shows up at tax time, and it is entirely avoidable.
Cleanup is expensive, because it is billed at professional rates. Buying bookkeeping from a CPA in February is the most costly way to buy it. When the books arrive reconciled, categorised and complete, those hours go to tax strategy instead.
Deductions your CPA cannot see are deductions your CPA cannot claim. Depreciation on a truck that was booked as an expense. Mileage that was never logged. Home office square footage nobody measured. Every missing piece is a missed deduction, and the money is gone by the time anyone notices.
If the IRS ever does look at your return, the documentation that survives is the documentation you had ready when you filed. Not the documentation you scramble to recreate two years later from memory and bank statements.
None of that is a tax problem. It is a bookkeeping problem that shows up at tax time.
Almost every year-end checklist online was written for a business that sells a thing, collects the money, and books the profit in the same month. Construction breaks all three assumptions.
Your jobs cross year ends, so revenue has to be recognised by how far along the work is rather than by what you invoiced. Your customers hold retainage, so a chunk of what you have earned is not collectable yet and needs its own treatment. Your costs attach to jobs, so a profit and loss statement without job-level detail cannot tell your CPA which work made money. You finance equipment, so a payment is part principal and part deductible interest, not one expense line.
A generic checklist has no line for any of that. Working through one gives you the comfortable feeling of being organised while the four items that actually change your return go untouched.
This is the single most important document on the list, and the one most likely to be missing. A work in progress schedule shows contract value, cost incurred, percent complete, earned revenue, billings to date, and over and under billings for every open job. It determines how much revenue you actually earned during the year. Without it, your income statement reflects billing timing rather than work performed, and the return is built on the wrong number. If you do not have one, our free WIP schedule template produces it.
Retainage held by your customers is money you have earned and cannot collect yet. It belongs in its own account, aged by job, with each balance verified against the current pay app. Netting it into general receivables hides it, and money that is hidden is money nobody chases. Old retainage is the most commonly forgotten cash in construction.
A company-wide profit and loss statement tells you whether the year worked. Job-level detail tells you which work worked. Without it your CPA cannot see which jobs made money, and neither can you, which means next year you bid the same way.
A financed truck is three entries, not one. The asset goes on the balance sheet, the loan goes on as a liability, and each monthly payment splits between principal and deductible interest. Contractors routinely expense the whole payment. That understates income, overstates the deduction, and creates exposure in both directions.
The nine sections below are the full list. Sections 1 through 8 are things you or your bookkeeper complete inside your accounting system. Section 9 is the pile of documents you hand your CPA once the rest is done.
Work them in order. The order is not arbitrary: reconciliation comes first because nothing downstream can be trusted until the accounts tie, and the document handover comes last because there is no point assembling it from books that are still moving.
If you cannot honestly tick a line item, that is not a reason to skip it. That is the exact problem to fix before you file, and it is almost always cheaper to fix in December than to explain in April.
In December there is still time to act on what your CPA tells you. In April they are describing what already happened.
December, not February. Several items can only be done properly before the year closes. A Section 179 election needs an asset that is bought and placed in service inside the tax year. Reasonable compensation for an S-corp owner is a payroll decision that has to happen while payroll is still running. Clearing Undeposited Funds and posting owner draws correctly is far easier when you are one month behind rather than twelve.
Starting early also changes the conversation with your CPA. In December there is still time to act on what they tell you. In April they are describing what already happened.
If most of these items are not things you could produce this week, that is worth knowing now rather than in filing season. It is a bookkeeping problem, and it is fixable, but not in the last week of January.
Our free 48 hour audit tells you exactly where your books stand before tax season. We identify every reconciliation that is not tying, every missed 1099, every deduction sitting in the wrong account, and hand you a written report inside 48 hours, whether you hire us or not.
This is general educational material, not tax or legal advice, and it is not a substitute for a conversation with a qualified CPA or tax attorney. Tax rules change every year, and items here may apply differently depending on your entity type, your state, and your specific facts. Some items depend on entity elections and may not apply to your business at all. Treat this as preparation for a conversation with your CPA, not a replacement for one.
Every account, every statement, tied out to the penny.
This is the foundation. If these reconciliations do not tie, nothing else in your books can be trusted.
Sales, deferred revenue, retainage and WIP, every dollar recognised correctly.
Construction revenue recognition is where generalist bookkeepers make the most mistakes. WIP and retainage need specific treatment.
Every direct cost tied to the job that generated it.
Without job costing, your CPA cannot tell which jobs made money and which lost it. This is also where most contractors accidentally overstate expenses by double counting or misallocating.
Every quarterly filing ties to the annual W-3 and every W-2.
Payroll mismatches are one of the top reasons the IRS opens a look at a construction return. Reconcile before you file.
Every subcontractor and vendor paid 600 dollars or more, correctly identified and reported.
Missing 1099-NECs generate IRS notices, penalties, and personal audits for the recipients. Get this right by January 31.
Trucks, equipment and tools, every asset properly capitalised and depreciated.
This is where thousands of dollars in tax deductions get lost. A financed truck that was expensed instead of capitalised costs real money.
Every loan payment split correctly between principal and deductible interest.
Only the interest portion of a loan payment is deductible. Contractors regularly expense the full payment, which understates income and creates audit exposure.
The everyday deductions that leave the biggest money on the table.
These are the deductions your CPA cannot find if you do not document them. Every one needs contemporaneous records: keep a log during the year, not reconstructed at tax time.
The pile you hand over once your books are prepped.
Bundle these into a labelled folder. Digital PDFs are fine and scanned copies are fine. Screenshots are not.
