How to Price Bookkeeping for General Contractors With Job Costing
How much should you charge for contractor bookkeeping with job costing? We break down the scope, the pricing models, and the traps that sink a flat fee.
Pricing bookkeeping for a general contractor is a recurring question in accounting forums, and for good reason. A contractor billing one to two million a year rarely has a simple file, and revenue alone will not size the work. We start every pricing conversation the same way: scope first, number second.
What does a general contractor’s bookkeeping involve?
Expect heavy accounts payable, dozens of subcontractor payments, progress invoices or draws, and a stack of compliance paperwork. Payroll can add prevailing wage reporting and union fringes. Two firms at the same revenue can differ sharply in transaction count, and transactions are what you price.
Most owners also want profit shown by job, and that is where the real time sits.
Should you charge hourly or a flat monthly fee?
Hourly is the safe start, because you bill what the file actually takes. A messy first quarter then comes out of the client’s pocket, not yours.
A flat monthly fee is easier to sell and easier to budget. It only works when you know the scope well enough to price it. Many firms land on a hybrid: flat for the recurring monthly close, hourly for cleanup and one-off projects.
What actually drives the hours?
- Transaction count: bills, card charges, and subcontractor payments in a normal month.
- Active jobs, since coding to ten projects takes longer than coding to three.
- The number of bank and credit card accounts, and how clean the feeds are.
- Payroll complexity, including prevailing wage jobs and union reporting.
- Subcontractor compliance: W-9 collection, insurance certificates, lien waivers, and 1099-NEC filing.
- Reporting depth: one monthly job cost report costs less time than a full work in progress schedule.
Does job costing change the price?
Yes, and it is usually the single biggest factor. Every cost line needs a project and often a cost code, so routine entry slows down.
Mistakes also surface fast. A bill coded to the wrong job distorts the margin report, and someone has to find and fix it. Budget time for that correction work.
Software plays a part too. In QuickBooks Online, project profitability reporting starts on the Plus plan. Desktop editions handle the same need through the customer:job structure. Agree on depth before quoting: full job costing, or lighter tracking with classes.
Quote from evidence, not from the revenue figure
Ask for a few months of real data before naming a number. Count the monthly transactions, the active jobs, the accounts, and the subcontractors. Confirm who runs payroll and which reports the owner expects.
Quote the cleanup separately. Most contractor files need catch-up work before the recurring service can start, and that work deserves its own line.
Put the exclusions in writing. Change order support, loan draw packages, and extra entities are common add-ons, not included work.
The traps that sink a flat fee
Scope creep arrives as small favors: one more report, one more entity, occasional CFO-style advice. Documents arrive late, or as a shoebox. Estimates versus actuals requests land mid-month.
Protect the fee with a review clause. A 90-day check-in lets you reprice honestly if the volume is heavier than either side expected.
Before you send the next quote
Pull one recent month of transactions and code a sample yourself. Time it, scale it to a year, and add margin for the surprises you cannot see yet. A quote built on evidence will hold up longer than any rule of thumb.