Hi there, John.
To associate an expense with a customer in QuickBooks Online, you first need to enable the Track expenses and items by customer setting. This adds a Customer column to your expense forms, allowing you to tag each expense line to a specific customer.
Here’s how to enable customer tracking for expenses:
- Go to the Gear icon and select Account and Settings.
- Click the Expenses tab on the left.
- In the Bills and expenses section, click the pencil icon to edit.
- Check the box for Track expenses and items by customer.

- Click Save, then Done.
Once done, you can now assign customers to your expenses:
- Go to + Create and select Expense.
- You'll now see a Customer column next to Category, Description, and Amount.
- For each line item, click the Customer dropdown and select the customer this expense relates to.
- Click Save and close.

Once you've associated expenses with customers, you can run the Profit and Loss by Customer report to see them. Here’s a visual reference:

If you have any other questions or need assistance with QuickBooks, feel free to click the Reply button below.