Nice to have you in the Community space, @Sim_D.

I appreciate you for sharing your insights on how to receive partial bill payments in QuickBooks Online (QBO).

Allow me to help and get the report you need. You’ll want to run the Open Purchase Orders Detail report. This report shows you the total amount of the Purchase Order (PO), the amount received, balance quantities, and the amount balance. Let me guide you how:

1. Go to the Reports menu.
2. Type in Open Purchase Orders Detail.
3. Click the Customize button.
4. Adjust the date under the Report period field.
5. Under the Group by field drop-down, select Product/Service.
6. Click the Change columns link and select Qty, Total Amt, Received Qty, Received Amt, and Open Balance.
7. Then click Run report. 

You can also use this link for more details about customizing reports in QuickBooks Online.

You might want to consider saving the current customization of your report. That way, you won’t have to go to the customization process again in case you need the same data in the future. For the complete steps, you can refer to this article: Memorize reports in QuickBooks Online.

Let me know if there’s anything else I can help you with running reports in QBO. I’d be more than happy to work with you. Have a great day ahead!