First, turn on the feature. In QuickBooks Online, go to Settings, then Account and Settings, then Advanced. Under the Categories section, enable class tracking. You can also turn on the option to warn you when a transaction hasn’t been assigned a class. Turn that on. It’s the only way to keep your data consistent because the moment you let transactions slip through without a class, your job site reports become unreliable.

Once tracking is enabled, create a class for each job site. Go to Settings, then All Lists, then Classes. Name them something your team will recognize. Using the customer name plus address works well for most contractors. If you’re running multiple phases on one site, you can create sub-classes under the main job site class to break things down further.

From that point forward, every transaction gets a class assigned. When you record an expense, pick the job site. When you create an invoice, pick the job site. When you enter a bill from a subcontractor or supplier, pick the job site. QuickBooks will add a class field to invoices, expenses, bills, checks, and journal entries. The discipline of assigning every single transaction is what makes this useful. Skip it on a handful of charges each month and your per-job numbers are off.

Run a Profit and Loss by Class report to see revenue and expenses broken out by job site. This is where the payoff happens. You can see which jobs are profitable and which ones are eating into your margins. Without this breakdown, your overall P&L might look fine while one or two jobs are quietly losing money.

One thing to be aware of is that QuickBooks Online also has a Projects feature, which is designed specifically for job tracking. Classes work across your entire chart of accounts and are great for high-level categorization. Projects let you attach transactions, time entries, and estimates to a specific job in one place. Many contractors use both. Classes for broader categories like service type or division, and Projects for individual jobs. If you’re primarily trying to track costs per job site, Projects might actually be the better fit depending on how granular you need to get.

For expenses that don’t belong to any specific job site, create a class called Overhead or General Admin. Rent, insurance, office supplies, and similar costs shouldn’t get forced into a job site class where they don’t belong. Having an overhead class keeps your job site numbers clean and gives you an accurate picture of what each project truly costs versus what the business spends regardless of job activity.

If you have a crew working across multiple job sites in a single day, split the transaction accordingly. QuickBooks lets you assign different classes to different lines within the same transaction. A supply run that covers materials for two job sites can be split on two lines, each with its own class.

Getting this set up correctly from the start saves a lot of cleanup later. If you’re already behind or unsure about the best structure for your business, QuickBooks Online setup and training can get your file configured properly so the data is useful from day one. And if your books need ongoing attention beyond the initial setup, our bookkeeping and tax services for contractors keep your class assignments accurate month after month so your job site reports stay reliable.