Importing XLIFFS for Translation

Hello,

My company is currently reworking our TechComm department and switching to an XML based system. Until now we have uploaded .mif files to WorldServer which are then entered into the workflow for translation and new terms added to the TM.

Our new process requires us to work with XLIFF files instead of mif. However we cannot upload our XLIFF files to WorldServer. From what I can find out, XLIFFs should be supported and added to the workflow the same way that we have been working up until now. What am I missing here?