An invoice is a commercial document that records transactions between a buyer and a seller. In QuickBooks, when users send invoices, they make sure that the company profile is complete. QuickBooks enables users to send invoices via email by default app “Outlook”. Sometimes when users try to send invoices, they can get affected because of certain issues such as QuickBooks Unable to Send Invoices Error. This error occurs due to incorrect settings of email preferences. If you want to get rid of QuickBooks Unable to Send Invoices Error, then you must run QuickBooks Diagnostic Tool and make sure to update the application with the latest version. Still, facing the error, then contact us at our toll-free number (844)-932-1139 to get an expert’s advice.