I've got your back, @SHSBookkeepers.

I have additional steps about running tag reports in QuickBooks Online (QBO). This way, you'll able to see the percent of company income for each tag quickly. 

As of the moment, we can only customize the Income by Customer Summary Report by specific Customers, Period Comparison, Report period, Accounting method, and Number format. 

As a workaround, we can customize the Profit and Loss by Tag Group Report to see the percent of company income for each tag. You can follow the steps outlined by CharleneMae_F above. But make sure to check the %Income box in the Rows/Columns section. 

See the sample screenshots below for your reference: 

Additionally, you can always Email, Print, and Export the report. So, you can use it outside QuickBooks or for future reference. For the complete steps, visit this page: Run reports.

To learn which reports are available for your version of QBO, check out this article: Reports included in your subscription.

Let me know if you have any other questions about generating reports in QBO. I'm always here to help. Keep safe.