My database (with ODBC backend) is used by around 10 users in distant locations. The db is written in Access 2010 and they all have the 2010 runtime installed--all works well. I am contemplating a move to Office 365 for on the development computer--will any of the runtime users encounter problems running the Access 365 versions on their 2010 runtime? If so, I need to keep one computer without the 365 installation--I assume I cannot run both on the same computer? I haven't been able to find out details of backwards compatibility. Thanks.