Welcome to the Community, @Schwarzstop. I can help you enter an activity taken on an account in QuickBooks Online (QBO).
You can visit your customers' profiles, where you can add notes to your conversations about overdue invoices.
Here's how:
- Sign in to your QuickBooks Online account.
- Hover your mouse to Sales, then select Customers.
- Choose the specific customer where you want to add notes.
- From there click on Add notes, under the customer's company name.
- Scroll down then once you reach the Notes and attachments field you can then enter some notes.
Moreover, you can visit this article for future help on how to gently remind customers about invoice due dates: Send invoice reminders automatically or manually in QuickBooks Online.
Please know that I'm just post away if you need any further assistance with managing your invoices in QBO. Don't hesitate to reach out. Stay safe.