In order to retrieve header/category rows (e.g. ASSETS, Current Assets) that have zero dollar amounts in QuickBooks Enterprise (QBE) Reports an additional parameter must be passed in the where clause of 'ReturnRows = 2'.
GET /reports where ReportName='Balance Sheet Standard' and ReturnRows = 2
By passing this additional field/value all rows are returned from QBE. It is important to note that these zero-value categorization rows are returned by QBE in a single array and are not maintained in the same sequence as how the data is displayed in QBE desktop. So depending on the specific business requirements additional effort must be made to format the response for user consumption.