How to Choose a Bookkeeper for Your Construction Business
A construction subcontractor doing $3 million a year can lose more to the wrong bookkeeper than the right one costs in a decade, and the losses never show up labeled as bookkeeping failures. They show up as a certified payroll rejected three weeks running while the GC holds a $140,000 pay app, as retainage nobody billed at closeout, or as a job everyone believed was profitable until the final numbers said otherwise.
We keep the books for subcontractors on bonded and prevailing wage work, and most of our construction clients arrived after one of those moments, not before.
This is a practical guide to making the hire well: what a construction-fluent bookkeeper actually does, the signs you have the wrong one, the questions that expose a generalist in ten minutes, and what this should cost.
What construction bookkeeping actually requires
Contract work breaks the assumptions generic bookkeeping is built on.
Revenue doesn't equal what you billed, because progress billings and earned revenue diverge on every job.
Money you've earned sits in retainage for months and needs its own tracking.
Labor isn't one payroll lump; it's job-level cost at burdened rates, and on public work it also has to reconcile to certified payrolls signed under penalty of perjury.
A bookkeeper who has never worked contract jobs doesn't do these things badly. They don't do them at all, because nothing in generic bookkeeping tells them these things exist.
The construction-fluent version: costs and labor tracked by job so margin is visible while jobs run, retainage receivable carried by contract on the balance sheet, invoices that mirror your pay apps, certified payroll produced correctly on covered work, and monthly reporting that shows which contracts are making money.
Signs you have the wrong bookkeeper
The clearest sign is that you can't get job-level answers. If "what's our margin on the school job" produces a shrug or a three-day delay, there is no job costing, and your bids are running on feel.
The second is retainage living outside the books. If your held money is tracked in a spreadsheet, or in your head, or not at all, closeout is a negotiation you enter without a number.
The third is certified payroll treated as an emergency. If covered work makes your office scramble every week, or payrolls keep bouncing on classifications and fringe math, the compliance layer is being improvised.
The fourth is labor at base wages. A crew member's real cost runs 30 to 50 percent above the wage once payroll taxes, workers comp, and non-billable time are included, and books that ignore the burden make every job look better than it is.
The fifth is your P&L recording billings as revenue with no adjustment for what's actually earned. That's how a company gets profitable on paper while overbilled across the schedule, and the difference surfaces at the worst possible moments: bonding renewals and job closeouts.
The questions that expose a generalist
Ask these before signing anything, and weight the specificity of the answers over everything else.
How many construction or trade contractors do you work with now?
How do you track retainage, and where does it sit on the balance sheet?
Have you produced certified payroll, on what forms, and how do you handle fringe credits and the overtime calculation?
Do you use burdened labor rates in job costing, and how do you build them?
How would you structure my books so I can see margin by job monthly?
How do you handle a pay app invoice so the books tie to the G702?
Is a CPA involved in the work, and in what capacity?
What's your response time when a certified payroll reporting deadline is Friday?
A construction-fluent answer to the fringe question takes two minutes and includes the word annualization.
A generalist's answer is a pause. That single question does more filtering than a reference check.
What this should cost
Real construction bookkeeping with certified payroll runs meaningfully more than generic small business bookkeeping, and the pricing tells you what you're dealing with. Full back-office engagements for subcontractors typically start around $3,500 per month, with certified payroll scoped per active project on top.
A quote at $400 per month for a $5 million sub isn't a bargain; it's a generalist who doesn't know what the work involves, and the difference gets paid later in held pay apps and cleanup fees.
The comparison points: a construction-experienced full-charge bookkeeper runs $65,000 to $80,000 a year in-house, fully loaded, if you can find one. National online bookkeeping services run cheap monthly rates and have never seen a certified payroll form.
The specialty firm sits between: the construction capability without the full-time cost, with CPA oversight the solo hire can't provide.
If your books are behind, expect cleanup to be scoped separately, commonly priced off the monthly fee times the months behind, with an incentive for signing on to ongoing service.
The fit works both ways
The best construction bookkeeping relationships have buy-in on both sides. The bookkeeper needs your office responsive, hours in on time for certified payroll, change orders papered when they happen, questions answered before deadlines, because compliance work dies without inputs.
You need the bookkeeper accessible, fluent, and honest about margins even when the news is bad.
In our own practice the first call goes both directions for exactly that reason: we're checking whether the office can support the rhythm, and you should be checking whether we know your world.
A bookkeeper who doesn't ask about your projects, your compliance load, and your office setup before quoting is quoting blind.
At Prophet Accounting, we run the full financial back office for construction subcontractors: bookkeeping and job costing at burdened rates, retainage tracked by contract, certified payrolls produced weekly under GC review, and monthly reporting that shows margin by job.
If any question in this guide got a shrug from your current setup, schedule a consultation at prophetaccounting.com/construction or give us a call at (772) 380-2871.
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Construction bookkeeping with real job costing typically starts around $3,500 per month for a subcontractor, with certified payroll scoped per active project on top. In-house construction bookkeepers run $65,000 to $80,000 annually fully loaded. Quotes far below these ranges usually signal a generalist who hasn't priced the actual work.
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For contract work, yes. Job costing, retainage tracking, progress billing, and certified payroll aren't variations on generic bookkeeping; they're separate capabilities a generalist has never needed. The gap shows up as rejected payrolls, invisible margins, and retainage nobody bills.
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Certified payroll is the weekly wage report required on public and prevailing wage projects, signed under penalty of perjury, covering classifications, base and fringe rates, and overtime. Most bookkeepers have never produced one. Ask specifically about fringe credits, annualization, and the overtime calculation; fluent answers are specific.
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Retainage should be tracked as retainage receivable on the balance sheet, by contract, separate from regular accounts receivable, so held money stays visible and gets billed at closeout. Retainage left in regular AR or tracked outside the books is the most common construction bookkeeping failure.
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Burdened labor is a worker's true hourly cost including payroll taxes, workers comp, and benefits, typically 30 to 50 percent above the wage. Job costing built on base wages overstates the margin on every job, which means bids priced on bad data.
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When you can't get margin by job monthly, when certified payrolls keep getting rejected, when retainage isn't on the balance sheet, or when your surety asks for schedules your books can't produce. Any one of those means the books have fallen behind the business.
