It means you would need to reconcile your bank account account with QuickBooks.

From the home page screen > company gear (upper right corner) > tools > RECONCILE

Do not try to force reconciliation. It will create more problems down the road.

Negative Balance could have contributed due to many reasons like missing […]

Resolution for 'balance off issue: 'how to get negative balance off quickbooks.' available: Yes.

The balance off issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the balance off issue yourself by looking for a resolution described in the article. If it is a complex balance off issue or you are unable to solve the issue, you may contact us by clicking here or by using other balance off support options.

For more information about resolving issues related to balance off in Quickbooks/QBO or to get support for the issue 'how to get negative balance off quickbooks.', click the link below: