During the Start a New Financial Year process, you will choose to keep or purge certain data from your company file.
If you choose to keep data from prior financial years, you will only be able to view -- not change -- the data. See How the company file changes when you Start a New Financial Year to see a list of transaction and entry types and how they are affected during the Start a New Financial Year process.
You can continue to keep one type of data -- closed transactions -- for up to seven years.
If you decide that you would like to keep data during the Start a New Financial Year process, but decide at a later time that you want to purge the entries, you can do so using the MYOB Accounting Purge command. You'll find the Purge command in the File menu of all command centres except the Banking Command Centre. (Purging information that's no longer needed)