When record locking is used in NetSuite’s WF, writing via CSV or external collaboration is not allowed.
If you want to control editing of approved vouchers, but record locking is too restrictive, you can use scripts to provide intermediate control. The specific methods are roughly as follows
(1) When a user opens a transaction in view mode: the edit button is hidden => direct modification is not possible because there is no edit button.
(2) When a user presses the edit button from the list and opens a transaction in edit mode ⇒ If the approval status is approved, an alert will be issued when the edit is saved and the transaction will not be saved.
Since this method restricts only direct editing by the user, it allows writing from external systems (e.g., delivery date responses from suppliers, etc.), thus enabling more flexible control than record locking.
If the standard functions do not fit your business, please consider adding scripts to your system, as it is often possible to achieve this.