The change will affect ".doc," ".xls," and ".ppt" documents created in Office versions 1997-2003, Google wrote on its . It affects Google Apps, Google Apps for Business, Government and Education.

The change could make it cumbersome for someone who uses an old version of Office and receives, for example, a XML-based ".docx" Word document from a Google Apps user, although Microsoft has long offered a to allow older Office suites to open the newer file formats.

It appears users will still be able to upload ".doc," ".xls," and ".ppt" file types. Google Apps of other non-Office file formats for downloading, including the OpenDocument specifications, PDFs and plain text (.txt).

Microsoft began using XML-based file formats starting with Office 2007 although it maintains compatibility with its older formats.