How do I create & save multiple types of invoices under one client/customer? So that I can just change the date, etc monthly?

Hello Jason,

Currently, we can only create one invoice at a time in QuickBooks Online. 

1. Click the Create menu (+) and select Invoice.
2. Choose the client name and enter the information.
3. Click Save and close or Save and new.

Meanwhile, you can also create a recurring invoice template that you can use anytime. You can follow these steps:

1. Click the Gear icon and select Recurring Transactions.
2. Click the New button and select Invoice in the Transaction Type field.
3. Click OK and enter the Template name.
4. Select Unscheduled in the Type field.
5. Enter the customer information.
6. Add the invoice details and click Save template.

In the Recurring Transactions window, you can click Use to manipulate and create the future invoices. Feel free to refer to this article for more information: Create Templates for Recurring Transactions.

I'll be right here if you need anything else.