Progress billing by project

Many of our projects are priced as "Not to Exceed" contracts by project. We progress bill the projects each month, but there's no automation to see if we've reached the Not to Exceed maximum. Hence, we may accidentally over-bill a client.

Please consider a project option to cap invoices at the maximum budget set, keeping a running total of all invoices created in prior months + current WIP. I understand there will be many projects for which a user may want to bill the additional fees, but the cap should be an automated OPTION either globally, within the project or within the invoice. Otherwise, we must track all project invoices sent prior months + current WIP = total - Not to Exceed price maximum = remaining amount we're permitted to bill on the project.