My customer received a payment reminder that must have been sent automatically. How do I turn this feature off?

Thank you for posting your concern here in the QuickBooks Community, Vcsinc. Let me assist you in turning off the feature of sending payment reminders automatically.

We can turn off and on this feature based on what you like. Let me show you how.

Follow these steps:

1. Go to the Gear icon.
2. Under Your Company, select Account and Settings.
3. Click Sales, and scroll down a bit.
4. Select Reminders, and click the pencil icon. 
5. Turn off or on this feature.
6. Click Save.

Moreover, I'd like to share these articles that might help you learn more about QuickBooks Online:

• Record invoice payments in QuickBooks Online
• Upload your receipts to QuickBooks Online
• Email receipts and bills to QuickBooks Online

I'll be here if you still have other concerns about your Invoices. Have a lovely day, and take care.