How do I resolve 'Tax could not be calculated: Object Reference not set to instance of an object' in QuickBooks Desktop?

Overview

You are trying to post an invoice in QuickBooks but receive error 'Tax could not be calculated: Object Reference not set to instance of an object'.

Environment

QuickBooks Desktop

Resolution

• Close QuickBooks
• Pull up the Task Manager and end any processes starting with "QB", "Intuit", "AV", "AvaTax", and "Avalara"
• Open QuickBooks
• Click File > AvaTax > Utilities, click Synchronize & View Unresolved Sales Tax Errors
  • Select the invoice(s) receiving the error
  • Click "Recalculate" or "Calculate All"
  • Invoice will display line Total sales tax calculated by AvaTax