This: "I would like to be able to report on the different types of income."
Would be the Charge Item. Not the Invoice.
You charge the customers, such as New Subscription vs Subscription Renewal.
Or, Customer Type or Job Type, such as "New" then changes to "Renewed. And Job Status = "Awarded" is New, and In Progress = ongoing, and Closed = left. Then, Job Dates for Start, End and Projected End, to manage notification for renewals.