Is it possible to lock sales order and other transactions after it is completed.
For example, if sales order is marked as delivered it is locked to prevent further changes in it.
I try to use lock date for this case but then user is unable to edit even if order is pending.
Not by status. Manager does not have a “lock this document when Delivered/Completed” feature. Sales orders are non-posting documents, so their editability isn’t controlled by operational status. The only built-in lock is date-based: Lock Date, which freezes transactions on or before a specified date. That protects prior-period data, but it isn’t conditional on whether an order is pending or delivered.