Payments processed in QuickBooks are being automatically charged to the oldest invoice. How do I turn this off?

If a Customer in EZRentOut has multiple outstanding invoices and you charge payment to one of these, QuickBooks automatically applies the amount to the oldest outstanding invoice. This is a QuickBooks Automation feature but if you’d like to manually apply payments to your choice of invoices, here’s how to disable it.

From your QuickBooks account, go to Gear icon –> Account and Settings –> Advanced –> Pencil/Edit icon against Automation. Here, disable the Automatically apply credits checkbox and save the changes.

For more details, read the QuickBooks FAQ for turning off automated payments.