Active

When Active, a particular Invoice Number Format  will be available for use within the system.  

De-activating an Invoice Number Format  that is currently being used on any project invoice setup screen or currently used to format an invoice number on a draft or completed invoice, will have no effect on those existing associations (that is, that Invoice Number Format  will continue to be the basis for determining the next available invoice number for those projects /  invoices).   De-activating an Invoice Number Format indicates that it will no longer be available to associate to any other new or existing project's invoice setup screens.

Essentially, de-activating a Invoice Number Format prevents it from being associated with anything that it is not already associated with.