New to NetSuite | Allow Non-posting Changes in Closed Periods by Default:

In NetSuite, closing an accounting period means changing its status from Open to Closed. A status of Closed indicates that posting transactions for the period have been completed. This status prevents posting to the general ledger for any dates included in the period, by anyone. Closing a period should be a final step, after a process of accounts review and reconciliation to ensure correctness and balance.

Accounting Periods now includes a preference called Allow Non-GL Changes Is Set by Default to allow non-posting changes in closed periods by default. When set, NetSuite checks the Allow Non-G/L Changes box for each new accounting period you create. Accounting periods created before setting this preference remain unchanged.