You asked Is there a way one can automate invoicing cutomers in advance with a schedule of different invoice amounts? (ie: June 1 = $200, July1=$3,000)

Hello, bobabbassi.

Currently, you' can create a scheduled recurring template for your different invoices. Let me guide you with the steps.

1. Click the Gear icon on the upper-right menu.
2. Under Lists, select Recurring Transactions.
3. Select New.
4. Select the type of transaction to create, and then select OK.
5. Enter a Template name.
6. Choose a Type: Scheduled, Unscheduled, or Reminder.

Please check this article for more information and steps: Create Recurring Transactions In QuickBooks Online.

For future reference, you can record invoice payments in QuickBooks Online: How to Record Invoice Payments.

Keep in touch if you need further assistance. We're always here to help you anytime.