QuickBooks Desktop does not require to close books as part of year end procedures. However, closing date allows you to limit access to closed accounting period by setting up closing date password.
Once you set up closing date password, QuickBooks Desktop requires the password every time you try to save any changes that will alter the balance of the closed accounting period. This includes adding, editing or deleting transactions within closed period.
You can set up or change closing date password anytime. If you lost or forgot the password, you can remove the closing date password as long as you are logged in as the Admin of the company file.