Question: Is it correct that confidential information should be kept under two locks, the filing cabinet and the office door?

Answer: The locking of both a file cabinet and an office door is not a legal requirement but a best practice. The reason that this is often suggested is that employers are required to take the necessary steps to protect employee confidential information and a double lock system provides a secondary layer of protection. Many file cabinet locks are very flimsy and can easily be broken. However, if you retain the confidential files in a sturdy cabinet with a lock that is secure enough that the company feels that they are providing adequate protection for the confidential information, then that would be considered acceptable.