We have a 3rd party quoting tool integrating with our QBO. When a sync creates an invoice in QBO, the invoice number is blank and our customer note field is blank.

QuickBooks Online (QBO) efficiently receives data based on the mapping configuration from your third-party tool, Rellison. You can verify this with their support team to confirm how their tool handles syncing invoices to QBO. I'll provide more details below to help you sort this out promptly.

Maintaining seamless operations and clear communication with your customers when it comes to their invoices is crucial. Since there are specific fields like customer notes and invoice number that were not entered, I highly recommend working with your third-party support team so they can help you in adjusting the field mapping. 

Meanwhile,  when the invoices still sync blank fields, you can manually enter the correct invoice number and customer notes into your invoices to ensure accurate records. Refer to this article for detailed steps: Create and send invoices.

In addition, after you process a payment from a customer, you need to record it in QuickBooks Online to mark the invoice as paid.

If you have more questions or concerns about managing your invoices in QuickBooks, please leave a reply below. We'd be glad to provide further assistance to help you complete your tasks.