What version of BIDS, Excel are you using? What version of SQL Server? I'm on SQL Server 2008 r2, Excel 2013 - I can't get this to work. I was able to Delete the content in the XLS - but then when the control flow tries to write output from SQL to the Excel destination (previously written to that same xls spreadsheet - but now deleted the tab content in a SQL Task) - the writing to Excel FAILS -- as the Excel "TABLE"/metadata/header row are now gone.