October 6, 2026 · Mitt Patel · 6 min read
You had a good month. Two service trucks ran calls all week and got paid at the door, and a construction job finally hit its second draw. The bank account looks healthy. But which one actually made that money, and which one is just riding along on the other's cash?
Why blending hides the real picture
Service work and construction work behave completely differently, even though they both show up as "electrical income" on a combined report.
A service call gets billed and paid the same day, often the same hour. A construction job gets billed in draws tied to milestones, and those draws might sit 30, 45, even 60 days before the check clears. If you run one set of books that mixes both together, your monthly income number is really two different stories smashed into one.
This matters because the two sides carry different costs, too. Service work usually has higher labor cost per dollar of revenue because you're paying for a technician's time and truck rather than materials. Construction work often has lower labor percentage but heavier material and subcontractor costs, plus the job has to survive weeks or months before it's fully paid.
When you blend them, a few bad things happen. First, you can't tell if service calls are subsidizing a construction job that's actually losing money once you account for callbacks, change orders, and slow pay. Second, you can't tell if a profitable service division is being starved of cash because construction draws are stuck in accounts receivable. Third, when someone asks "should we take on more construction work or focus on service," you're guessing instead of looking at numbers.
The owners who get surprised are usually the ones who feel busy and profitable on paper, then find themselves short on cash for payroll because a big construction job hasn't paid out yet, and nobody was tracking that separately from the steady service income covering the gap.
A worked example
Say your electrical business runs both service calls and a mid-size construction job in the same month.
Service side: you ran 40 service calls, billed at an average of $300 each, so $12,000 in revenue. Labor and truck costs for those calls ran $7,200, leaving a gross margin of $4,800, or 40%.
Construction side: you're partway through a job billed at $30,000 total. This month you hit the second milestone and invoiced $10,000. Materials and subcontractor costs for that stage came to $7,000, and your crew's labor was $1,500. That's $8,500 in costs against $10,000 billed, a gross margin of $1,500, or 15%.
Combined, your books show $22,000 in revenue and $15,700 in costs, a blended margin of about 29%. That number looks fine. But it hides that service work is carrying about three quarters of the profit dollars ($4,800 of the $6,300 total) on just over half the revenue, while construction is running thin margins and the $10,000 invoice might not actually get paid this month at all, depending on when the general contractor or homeowner releases the draw.
If you didn't split these, you might look at "29% margin, $22,000 in revenue" and think business is steady. Split apart, you can see service work is the stronger performer per dollar, and the construction job needs a hard look at whether 15% margin is worth the wait for payment and the risk of a slow-paying client.
How to set it up
- Create separate income accounts. In your chart of accounts, set up "Service income" and "Construction income" as distinct lines instead of one general "Electrical income" account.
- Mirror the split on the cost side. Create matching cost categories: "Service labor," "Construction labor," "Construction materials," "Construction subcontractors," and so on. The goal is to be able to calculate gross margin separately for each side.
- Tag every invoice and bill at entry. When you write an invoice or enter a bill, assign it to the right income or cost account right away. If you use QuickBooks Online, the class or location tracking feature works well here, letting you tag each transaction as "service" or "construction" without duplicating your whole chart of accounts.
- Track accounts receivable by job for construction. Because construction bills in stages, keep an eye on what's been invoiced versus what's been collected for each job. A simple aging report will show you which draws are overdue.
- Run a monthly profit and loss by class or category. Once transactions are tagged, pull a report that shows service and construction side by side. Compare gross margin percentage, not just dollar totals.
- Watch cash timing separately from profit. A construction job can be profitable on paper and still cause a cash squeeze if the draw hasn't cleared. Keep a simple note of expected payment dates for open construction invoices so you're not caught short.
Mistakes that undo it
- Tagging invoices after the fact, or not at all. If tagging becomes an afterthought, your reports quietly slide back into being blended, and you won't notice until you go looking for a number that isn't there.
- Splitting income but not costs. Some owners track service and construction revenue separately but leave all labor and material costs in one bucket. That still hides which side is actually profitable.
- Ignoring partially billed jobs. A construction job that's 60% complete but only 40% billed will look worse than it is if you're not tracking percentage of completion separately from cash billed.
- Forgetting overhead entirely. Gross margin by side leaves out rent, insurance and the office, which is fine for comparing service with construction. But both sides together have to cover that overhead, so check the combined gross margin against it before growing either one.
Monthly checklist
- Confirm every invoice and bill from the month is tagged as service or construction
- Pull a profit and loss split by service and construction
- Compare gross margin percentage for each side, not just revenue
- Review open construction invoices and note expected payment dates
- Check whether service income is covering payroll while construction draws are pending
- Flag any construction job whose margin has dropped below what you'd expect
Common questions
Do I need two separate QuickBooks files for this?
No. One file works fine. Use class tracking or location tracking inside QuickBooks Online to separate service and construction without maintaining two sets of books.
What if a technician does both service calls and construction work in the same week?
Split their time and pay between the two categories based on hours worked on each type of job. It takes a bit more discipline in timekeeping, but it keeps your labor costs accurate on both sides.
How do I handle overhead costs like rent and insurance?
There's no single right answer here since it depends on how your business is structured. Some owners split overhead evenly, others by revenue share, others by headcount. The important thing is picking one method and applying it consistently, so your margin comparisons mean the same thing month to month.
Is construction work always lower margin than service work?
Not always. It depends on how the job was bid, how well change orders were tracked, and how long the draws took to collect. That's exactly why tracking them separately matters. Without the split, you're guessing instead of knowing.
North Hudson Bookkeeping sets up this kind of split for electrical contractors and keeps it current every month, so you have clearer visibility into which side of the business is paying the bills. The first call is free.
