Sales By Item Summary, Previous Year Comparison

Hi there, @joshlapin.

At this time, there isn't an option to compare multiple months from previous years when running the Sales By Item Summary report.

As a workaround, you can consider selecting each month from the previous years and exporting it to Excel. Then, combine the data from the Excel file and compare it from there. Here's how to export a report:

1. Open the Sales by Item Summary report.
2. In the Date section, enter each month from the previous years.
3. Once done, click Excel and select Create New Worksheet.

I'm adding this article for more guidance: Export reports as Excel workbooks in QuickBooks Desktop.

Just in case you encounter issues exporting reports to Excel, you can read this article to know how to fix it: Fix export to Excel issues in QuickBooks Desktop.

Please know that I'm just a reply away if you need any further assistance running reports in QuickBooks Desktop. Wishing you all the best, @joshlapin.

@joshlapin 

The Sales by Item Summary report is a special canned report where you can't add last year.  If you could add last year and show by month, the report would be very wide. Almost not useful.  But, if you don't need all the columns on the report, you can create a custom summary report and include the Qty and Amount columns, then total by month and include last year.