System Locks apply restrictions to working with a quote once it has been accepted, and when orders can be archived.
Click: System Config > System > System Locks
Tick the box to enable the following locks:
Don't allow the customer to be changed once the quotation has been accepted
This lock applies across the system and does not depend on the username.
Don't allow an order to be archived while there is a balance outstanding
The option to archive (which involves moving data to another EQ dataset) would be disabled for any orders whilst there is still a balance to be paid
Don't allow an order to be archived unless the invoice has been raised
The option to archive (which involves moving data to another EQ dataset) would be disabled for any orders until they have been fully invoiced
Click Update to save and close.