Hey there, @curator1! I'll share some information about correcting the customer opening balance so you can continue doing your other QuickBooks tasks.
Yes, changing the customer opening balance is possible by editing the generic invoice linked to it. Before doing this, it's essential to consult an accountant to avoid discrepancies in your book.
Here's how:
- Hover your mouse to the Customer & leads option and select Customers.
- Pick a client.
- Find and choose the Opening balance invoice.

On the other hand, you can review the setup of your Journal Entry (JE), see if the Credit and Debit columns are correct, and check if you've interchanged the accounts that caused the issue. The thing is, you can correct it with the guidance of your accountant.
Additionally, consider reading this article to learn how to show your customers the summaries of their invoices, payments, credits, and balances: Create and send customer statements in QuickBooks Online.
The Community door is always open for additional questions about managing customers' opening balances to ensure accurate data reporting. I got you! Take care and enjoy your day, @curator1!