The biggest thing that sets HVAC and plumbing bookkeeping apart from other businesses is the mix of revenue types. You have service and repair calls that are quick, one-time transactions. You also have larger installation or new construction projects that play out over days or weeks. Your books need to separate these revenue streams so you can see the margins on each. A company doing $1.2 million in revenue might look profitable overall but be losing money on installs and making it all back on service calls. You won’t know unless the books are structured to show it.

For service calls, the bookkeeping is relatively straightforward. Revenue comes in, parts and labor go out. The key is making sure every transaction gets categorized properly and that you’re tracking the cost of parts used on each call. If your techs pull parts from a truck or warehouse without recording what was used, your inventory numbers drift and your true cost per job is a mystery.

Larger projects need job costing. Each installation or bid project should be tracked as its own job in your accounting software so you can see labor, materials, and any subcontractor costs against the revenue for that specific project. This is how you figure out which types of jobs are actually worth pursuing and which ones you’re underpricing. A QuickBooks ProAdvisor in Chandler can set up your chart of accounts and job tracking so this data flows naturally without creating extra work for your office staff.

Seasonal cash flow is a real concern, especially for HVAC. Summer in Arizona means the phones don’t stop ringing for AC repairs and replacements. Winter slows down considerably. Your bookkeeping should feed into a basic cash flow forecast so you’re setting aside money during busy months to cover the slow periods. Too many skilled trades businesses spend everything they earn in the summer and then scramble to make payroll in January.

Payroll deserves attention too. Technicians often earn overtime, and some shops pay flat rate or commission on top of base wages. Make sure your payroll is set up correctly and that labor costs are allocated to the right jobs. Misclassifying employees as contractors is another common issue in the trades that creates serious tax problems down the road.

Vehicle and equipment costs add up fast when you’re running a fleet of service vans. Track fuel, maintenance, insurance, and depreciation for each vehicle if possible. This helps you decide when it’s time to replace a van instead of sinking more money into repairs, and it gives your tax accountant the documentation they need to maximize your deductions.

Reconcile your bank and credit card accounts monthly without exception. Trade businesses tend to have a high volume of supply house charges, fuel purchases, and small vendor payments that are easy to lose track of. Monthly reconciliation catches duplicate charges, missed deposits, and transactions that slipped through without being recorded. The longer you wait to reconcile, the harder it is to figure out what happened and the less reliable your financial picture becomes.