Milestone / Project Billing - Deposit Invoice

Hi all - hoping there are some project management / project billing experts on here to help with this situation.

We are currently using the Project Management module to manage our projects and, within that, we are using milestone billing to create advanced billings when certain benchmarks are reached. We aren’t using WBS phases for these benchmarks, though they certainly could be because our benchmarks are most often things like “Acknowledgement of PO”, “Engineering Completed”, etc.

Consider a project with a single sales order structured like this:

Line 1, Part # ABC - $50,000
Line 2, Part # DEF - $50,000
Line 3, Part # GHI - $50,000

All three of these products are engineered to order and we have agreed to a 10% milestone to be paid when engineering is completed for all three products. We would like to have the milestone billing here apply to the sales order as a whole, or be easily spread across the 3 relevant lines.

Currently, we are handling this situation by creating a milestone for $5,000 against each of the lines. To invoice this, though, requires the creation of 3 individual AR invoices (1 milestone per invoice) which is unnecessarily burdensome for our AR team and our customers.

We would like to be able to consolidate this into one deferred revenue invoice for 10% of the entire sales order value ($15,000), if possible. We have the project billing module as well, but I’m not seeing any way for those additional billing options to help with our situation.

Thank you for your help in advance.