If you have super in other funds, you can combine them, meaning less paperwork and reduced fees which can make a difference to your total super balance when you are ready to retire.
Contributing members can elect to transfer amounts held with other funds into their CSS account. These amounts will be treated as a separate accumulation amount and can only be paid in lump sum when you claim your benefit.
Visit the ATO website for ways to check and manage your super. To transfer amounts into your CSS acount you will need the Unique Superannuation Identifier (USI) of the CSS fund which is 19415776361001.