Hi there, PrecisionCleaning.

I've got some details with you about turning off reminders in QuickBooks Online (QBO).

We have received several reports regarding this, and our Product Engineers are now working to fix it as quickly as possible. While they do, I recommend reaching out to our Customer Care Team, so you'll be added to the list affected users (INV-53255). 

To reach them, click the ? Help button at the top-right corner and select Contact Us to talk with a live agent. Ensure to review their support hours so, you'll know when agents are available.

For your future task, here's a resource for guidance when receiving customer payments: Record invoice payments in QuickBooks Online.

Thank you for your patience while we work for a fix. If you have additional assistance while managing your QuickBooks account, let me know. I'll be around to provide further assistance. Have a nice day.