Why can't i Group By invoice number? I can see almost any other column available except this.

You raised your issue in the right forum, @finance-support-. Allow me to help you ensure that the Invoice number column in the report will display.

Before anything else, I'd like to know what report you run in QuickBooks Online (QBO).

Please know that the Invoice number column isn't in the Group by section. Rather, you can find it in the Column tab as Num (Number).

To include this in the report, ensure it's ticked with the green checkmark. You can use the sample images below as a reference.

For the Modern View:

For the Classic View:

Moreover, you can read this article to learn how to save the customization of your report for future use: Memorize reports in QuickBooks Online.

Don't hesitate to reply to this post if you have additional questions about customizing the display of your report. We'll be willing to assist you as soon as possible. Keep safe, and have a good one.