Hello, al252.

Thank you for reaching out for assistance with the issue you're encountering with duplicate invoices and discrepancies in your reports. I'll ensure to offer help to resolve this.

It’s crucial to double-check the period settings of the reports you're generating. Sometimes, incorrect date ranges can lead to zero sales showing up in reports even though transactions exist.

To verify and adjust the reporting period:

1. Open the report you are analyzing (Sales by Customer or Profit and Loss).
2. Look for the report period settings, usually found at the top or in the settings menu of the report.
3. Ensure that the dates correctly represent the period you want to review. Adjust them if necessary and rerun the report.

If the date range is correct and yet the issue persists, there is a possibility that there may be an underlying issue with your company file that could be causing these discrepancies. I recommend using the Verify and Rebuild Data utility tool available in QuickBooks Desktop (QBDT) to help identify and correct any data integrity issues with your company file.

Here’s how to run the Verify and Rebuild tool in QBDT:

1. Go to the File menu, click on Utilities, and then select Verify Data. Allow the tool to check for any issues with your data.
2. If the Verify Data tool finds issues, run the Rebuild Data tool. Go back to the File menu, click on Utilities, and then select Rebuild Data.
3. Follow the prompts to create a data backup and allow the tool to fix any detected issues.

After completing these steps, please re-run the Sales by Customer and Profit and Loss reports to check that the data is accurately reflected.

I also recommend reconciling your accounts. This step is essential to ensure that the entries in your QuickBooks align perfectly with your actual bank and credit card statements.

If you continue to encounter issues or need further assistance navigating this process, please don't hesitate to post them in the comments, al252. We are committed to helping you ensure that your financial reports accurately reflect your business activities.