Let me guide you through the process of removing the payments made in January 2024 to get to the actual amounts outstanding on 31st December 2023, Sharon.

Please take note that if you pay any invoices in January 2024, they will not appear as outstanding in the report that ends on December 31, 2023. This implies that once we make the invoice payments in January, QuickBooks will recognize them, and the customer's actual balance for that month will no longer be displayed, even if you set the reporting period accordingly.

As a workaround, we can apply a filter to show the customer's balance and payment status. In this case, you can run the Invoice list report. If you're using the new interface of QuickBooks Online, select the Switch to classic view for more options. From there, follow the steps below:

1. On the Invoice List report by Date Report, press Customize.
2. Set the date on the Report period.
3. Select the Open Balance, A/R Paid, 
4. Tap the Rows/Columns dropdown to tick the Open Balance, Due Date, and A/R Paid.
5. Under the Filter section, put a checkmark on the A/R Paid and Terms. 
6. Click Run report.

Review the ageing method to determine if you need to categorize outstanding receivables by days past due based on today or the report date. Scan this article for a detailed overview of their balances: Run an accounts receivable ageing report.

Here's a reference to get the most out of your financial reports: Customise reports in QuickBooks Online.

In case you need additional assistance running aging reports, feel free to add a comment below. I'm just a few clicks away to help. Have a productive day ahead.