Hello, info18.
QuickBooks Online recognizes the last invoice number recorded. It's possible that a user created an invoice with a different invoice number. You can check it in the Audit Log report. Here's how:
- Click the Gear icon.
- Choose Audit Log.
You can reset the invoice number counter to resolve this. When you create a new invoice, you'll have to manually enter the right number so the sequence will be corrected.
Drop by anytime if ever you need help with QuickBooks Online. Have a nice day!