How do I set up expense accounts for each sales category so I can track each the profitability of each service?

Hello @usermattdeacon,

Thank you for posting here in the Community. I can provide some clarification about the categories in QuickBooks Online.

Currently, the option to set up an expense account for a product category is unavailable. However, you can add it to the purchasing information of the service item.

Here's how:

1. On the left navigation bar, click Sales.
2. Search for the service item.
3. Press Edit under the Action column.
4. Put a checkmark to the box next to I purchase the product/service from a supplier.
5. Add the expense account.
6. Hit Save and close.

The categories groups your products and services when you run sales or stock reports. You can use the Sales by Product/Service Detail report to track the profitability.

Please follow these steps to run the report:

1. On the left navigation bar, click Reports.
2. Select Sales by Product/Service Detail under Sales and customers.
3. Enter the report period.
4. Make the necessary changes to the filters.
5. Hit Run report.

For additional reference, I've attached a link you can visit for tips about how to handle categories when running reports: Group your products and services into different categories.

Feel free to hit that Reply button if you have further questions regarding the sales categories in QuickBooks. Have a great day ahead.