In MYBOS, closing an accounting period is not required, but you can lock accounting periods to prevent any changes.
For example, if you want to prevent any changes to accounting transactions before 01/01/2015, go to Settings tab.
Click Lock Date.
Set Lock Date to 31 December 2014 and click Update button.
Now, if you try to edit or delete any transaction dated on or before 31 December 2014, you will see following notice.
You can temporarily remove the lock date if you need to edit or delete a transaction. Enter the lock date again when you have completed the changes to previously locked transactions.
Lock Date is useful in multi-user editions of MYBOS to prevent restricted users from modifying transactions in a locked period. You should ensure the Lock Date feature is disabled for restricted users to prevent them from unlocking the period.