Invalid Customer ID or LVL_ERROR in QuickBooksTable of Contents1 Invalid Customer ID or LVL_ERROR in QuickBooks2 Solution for Invalid customer ID and LVL_Error Invalid Customer ID or LVL_ERROR occurs when Intuit servers detect an invalid customer ID with Online services like Banking.  This error code is found in the Log files of QuickBooks i.e. Qbwin.log, … Continue reading How to fix Invalid customer ID error or Log file (Qbwin.log) LVL_ERROR