Hello there, cool1025. 

You can have custom invoices and estimates by running the Transaction Detail by Account report. Then, customize the report by following these steps:

1. Open the Transaction Detail by Account. Go to Reports > enter the name of the report in the search box.
2. Click the Customize button.
3. Select the Group by drop-down arrow. Then, select Customer.
4. Add the Customer column as well as the Product and Service.
5. In the Filter section, click the Transaction Type drop-down arrow. Then, select Invoice and Estimate.
6. Then, hit Run report.
   

You'll see the invoice number will show up multiple times depending on how many line items are added to it, as well as the estimate. To make a custom report, utilize the Save customization button. Check here to view the complete steps and information on how you can do it.

Here's an article that you can check anytime to learn more about QuickBooks Online reports: Learn how to get the most out of your financial reports. 

Post again if you have other questions about QuickBooks. I'm right here whenever you need help. Take care always.