Construction Bookkeeping: A Contractor's Plain-English Guide

I run a remodeling company and I built a job costing app, so I have now been on both sides of this: the guy with a truck full of receipts, and the guy reading the code that adds them up. The thing nobody told me early on is that construction bookkeeping is not harder than other bookkeeping. It is just one layer deeper. A restaurant needs to know what it spent on food last month. You need to know what you spent on food last month and which of your six jobs ate it.

Miss that second part and your books can be perfectly balanced, perfectly reconciled, accepted by your CPA without a single question — and still completely unable to tell you the only thing you actually wanted to know, which is whether the Miller bathroom made money. That is the whole ballgame. Everything below is in service of it.

What makes construction bookkeeping different

Five things. If you understand these five, you understand why generic small-business bookkeeping advice keeps not quite fitting you.

1. Every cost belongs to a job. Not just "materials" — materials, Henderson kitchen. This is job costing, and it is the difference between a P&L that says you had a good year and a report that says which four jobs carried the other eleven.
2. You get paid in pieces. Progress billing means money arrives against percentage complete or milestones, not on delivery of a finished thing. Your cash coming in and your costs going out are on different clocks, permanently.
3. Retainage.On bigger and commercial work, a slice of each payment — often 5–10% — is held back until the job closes out. It is money you earned, invoiced, and cannot spend. It has to be tracked as its own thing or you will quietly believe you were paid in full on a dozen jobs.
4. Subcontractors mean 1099s. Every sub you pay $600 or more in a year needs a 1099-NEC, which means you need a signed W-9 from them before you cut the first check. January is the worst possible time to start chasing a framer for a tax ID.
5. The paperwork is generated in a truck.Not at a desk. Supply-house tickets, dump receipts, a plumber's invoice photographed in a driveway. Any system that requires you to be sitting at a computer to record a cost will lose costs, because that is not where the costs happen.

The chart of accounts a contractor actually needs

Most contractors have one of two problems: a chart of accounts with 4 lines, or one with 400. Both fail for the same reason — neither one tells you where the money went in language you use on a jobsite. Here is the shape that works, and the key idea is the split between job costs (they belong to a job) and overhead (they belong to the company).

That is roughly ten buckets, not four hundred. The depth you need does not come from more accounts — it comes from tagging each cost to a job. Ten buckets times your active jobs gives you every report you will ever ask for, and you can still recognize your own books.

One warning that costs real money: if your crew's wages sit in a single "Payroll" overhead line, every job on your books is fictionally profitable and your company is mysteriously broke. Labor is a job cost. Getting hours onto jobs is usually the single biggest accuracy win available to a small contractor.

Cash or accrual — and why you keep getting told accrual

Cash basis records income when the check clears and expenses when you pay them. Simple, and it matches your bank account. Accrual records income when you earn it and expenses when you incur them, whether or not money has moved.

Contractors get pushed toward accrual for one reason: your jobs cross months. You buy $14,000 of tile in March and get paid for it in May. On cash basis, March looks like a disaster and May looks like a triumph, and neither month is telling you anything true about the job. Accrual puts the cost and the revenue in the same place, which is the only way percentage-complete reporting makes sense.

There is a real middle ground a lot of small remodelers live in: cash basis for the tax return, job-level cost tracking running alongside it for management. Your books stay simple; your job numbers stay honest. Which one is right for you is a conversation with your CPA, not a blog decision — revenue size and job length both affect what the IRS expects of you.

The monthly close, in a contractor's week

"Closing the books" sounds like an accounting ritual. In practice, for a small shop, it is about ninety minutes and five moves:

• Reconcile. Bank and credit-card statements against the books. If they do not match, nothing downstream is real.
• Chase the missing receipts. Every card charge without a receipt is a deduction you may not be able to defend and a job cost that landed in the wrong place. This is the step everyone skips and the step that pays.
• Get hours onto jobs. Payroll for the month, split across the jobs the crew actually worked. Reconstructed-from-memory hours are the second-biggest source of wrong job numbers.
• Invoice what you earned. Progress billing does not send itself. This is also when you look at retainage — what is being held, on which jobs, and whether any of it is now releasable.
• Read the job reports, not just the P&L. Estimate vs. actual on every open job. A job that is 70% spent and 40% built is telling you something while you can still act on it.

Do that monthly and you are ahead of most of your competition. Do it weekly on the receipts step and you will never have the March panic again.

DIY, software, or hire a bookkeeper?

This is the real question behind most searches for this topic, so here is the honest version. There are three stages and most contractors pass through all of them.

The trap in the middle row is worth naming. Software does not fix bookkeeping; it fixes arithmetic. If costs still reach the system late and from memory, you have simply bought a faster way to be wrong. What makes the software stage work is capture at the moment of spending — the receipt photographed at the supply-house counter, the hours clocked on site — so the books are being written by the job as it happens.

What does a bookkeeper actually cost?

Google's own "people also ask" box on this topic includes "Is $300 a month reasonable for monthly bookkeeping?" — so let me answer it instead of dodging it. For a small contractor, monthly bookkeeping commonly runs somewhere in the low hundreds to around a thousand dollars a month depending on transaction volume, number of jobs, whether payroll is included, and whether you are handing over clean data or a shoebox. Under that range you are usually buying data entry; well over it you are usually buying a controller-level relationship.

So: is $300 a month reasonable? For a one-or-two-crew remodeler with tidy inputs and no payroll processing, that is a plausible number, not a red flag. For a shop running eight jobs, a crew, and a stack of sub invoices, $300 is probably buying less than you think it is. Get quotes from two or three people who have done construction specifically — retainage and job costing are where general bookkeepers get lost — and ask each of them how they will handle those two things. The answers will separate them fast.

The other half of the math nobody mentions: whatever you pay a bookkeeper, you also pay in the quality of what you hand them. A month of clean, job-tagged costs takes a fraction of the time to process than a month of mystery charges, and you get billed accordingly. The cheapest bookkeeping is the kind that arrives already sorted.

The mistake that costs the most

Not fraud. Not a botched reconciliation. It is costs that never reach a job at all.

I priced a bathroom at $42,000 believing I was carrying a 30% margin, and finished it at 12%, because about $7,500 of real receipts never made it onto the job. My books balanced. My accountant was happy. The money was gone and I had bid the next three jobs off the same wrong number, which is the part that actually hurts — one bad cost record does not cost you once, it costs you on every job you price after it.

That is the case for treating expense trackingas bookkeeping's front door rather than its afterthought. If you want the deduction side of the same habit, see how to organize receipts for taxes and the construction tax-deduction checklist — filing a receipt for the deduction and filing it to the job are the same act, done once.

Where software fits, honestly

QuickBooks is where most contractors end up for the books of record, and it should be — your CPA speaks it, and job costing in QuickBooks genuinely works once it is set up. Its weak spot is not accounting, it is capture: costs land when somebody sits down and enters them, which is days or weeks after the jobsite.

That gap is what I built Job Cost Pro to close. Snap the supply-house receipt at the counter and the AI files the line items to the right job; the crew clocks in on site so hours land at real cost; every job shows a live margin instead of a year-end surprise. Then it exports into QuickBooks — it feeds your books, it does not replace them. It does not do estimating or scheduling, and it is iPhone only today. Free on the App Store: 3 projects, 50 receipts a month, AI scanning included, no card. Get it here.

One last thing, said plainly: none of this is tax or accounting advice. I am a contractor who got tired of not knowing his own numbers, not your CPA. Rules and thresholds change, and your situation has details a blog post cannot see. Use this to ask better questions of a professional who has looked at your actual books.