Scenario
The Company wants to shift from a Calendar Year to a Fiscal Year.
Solution
Changing the Accounting Period from Calendar Year to Fiscal Year is not doable in the NetSuite User Interface because of the possible effect of this most especially if there are Historical/Posted Transactions.
The best approach is to coordinate with the Professional Services Team via the Customer's Account Manager as change in Accounting Period, most especially those which already have records in it, would involve modifying Child Accounting Periods and clearing of associated Transactions. The impact of such a modification should be considered first before proceeding with the change.