We can run the Uninvoiced charges report, rogeraf.

This report displays the list of your billable expense charges. Then, we can filter to show only the data for the specific customer.

I'll show you how:

1. Click the Reports tab.
2. Enter and select Uninvoiced charges in the Find report by name search box.
3. Click Customize.
4. In the Rows/Column drop-down, select Customer.
5. Go to the Filter drop-down.
6. Tick Transaction Type and select Billable Expense Charge.
7. Select a customer in the Customer drop-down.
8. Click Run report.

I've also added these articles that talks about Projects in QuickBooks Online:

• Projects FAQ
• Set up and create projects

You always have me if you still need my help!