We sometimes have invoices or estimates we'd like to "lock" or "freeze" from being altered, except by a specific user/group.

Example: An employee buys something through the store and will be paying back over time. We don't want anyone to be able to go into the invoice and delete line items over the course of the repayments.

This would be a similar solution as "Finalize" in ticket worksheets. A button that would disable adding/editing/deleting any kind of line items, descriptions, prices, etc. Only specific security groups would have the ability to "lock/freeze", and others would have the ability to "unlock/unfreeze".

Simple, effective, and powerful. Please consider.