Lock date
Menu: Administration → Lock Date Settings

Global lock date
Applies to every module unless a module has its own setting.
Click Save changes.
Example: After filing GST for September, set the lock date to 30 September. Set Max Backdate Days to 3 so staff can’t enter bills older than 3 days.
Per-module overrides
Set a different Override Lock Date and Max Backdate Days for a module, such as Sales, Purchase, Memo / Erattu, Metal Receipt or Journal Entry. Click Save on that row. Modules showing Unrestricted use no limit of their own.
