Installment Invoices before Shipment

Thanks for raising this — it's a very relevant scenario, especially in manufacturing and custom machinery, as you mentioned.

You're right that Acumatica's current behavior doesn't support generating installment invoices prior to shipment when using standard Credit Terms with installments or Prepayment functionality.

A possible approach would be to develop a small customization that simulates this process. The idea would be to:

• Automatically generate Prepayment Invoices based on the installment schedule.

• Allow users to release and apply each prepayment according to the agreed timeline, even before shipment occurs.

• Optionally, display installment-related data for better visibility and traceability.

This would allow you to respect the installment logic while creating invoices ahead of shipment.

Just a suggestion that might help bridge the current limitation 

I could make use of this functionality as well.  We often require customers to make deposit and progress payments for custom items 

You're absolutely right — this is very common in manufacturing and capital equipment sales, where customers pay installments or progress payments before shipment. Acumatica doesn’t handle this scenario natively in a way that ties Installment Terms with pro forma or pre-shipment invoices, but the good news is: there are workable solutions with a few configuration and process adjustments. Let’s break it down clearly.

🚫 Core Issues You’ve Identified (Confirmed ✅)

1. Prepayments are not allowed when Credit Terms use Installments.
2. Installment Invoices are only generated during normal AR Invoice processing, which happens after shipment (SO → Shipment → Invoice).
3. You need to create invoice(s) before shipment, based on Installments or a project-like schedule.

✅ Goals

• Generate installment invoices before shipment
• Use installment logic (due dates and amounts)
• Allow shipments later, possibly tied to completion or balance payment

🛠️ Solution Options

🅰️ Approach 1: Use Manual AR Invoices + Installment Terms

This is the cleanest workaround using native features:

✅ Steps:

1. Create an AR Invoice manually (not from SO) for each installment milestone:

Receivables → Work Area → Invoices and Memos → +New Invoice

2. Assign the Installment Terms on the Invoice header (they will be honored here).
3. Manually tie the AR Invoice to the Sales Order (via customer ref or notes).
4. At the time of shipment, create a $0 AR Invoice or a final balancing invoice if needed.

✅ Pros:

• Uses installment terms as designed
• You get scheduled due dates and amounts
• Invoices can be posted before shipment

⚠️ Cons:

• Not directly tied to SO → Shipment flow
• You must prevent shipment until X% paid (manual control or workflow)

🅱️ Approach 2: Use Prepayments + Custom Payment Schedule GI

If you want to stay within SO flow and collect early payments:

Setup:

• Use regular Terms (e.g. Net 30) on SO
• Enable Prepayments on the Customer
• Create multiple Prepayments manually (one per milestone)
• Build a Generic Inquiry to track payment schedule

🧩 Optional Add-on:

Use Project Module or Contract-based billing if payments must be tied to phases or deliverables.

✅ Pros:

• Payments are recorded against SO
• Flexible timing
• Shipment can still be blocked via prepayment rules

⚠️ Cons:

• Can't use Installment Terms (as you noted)
• No due-date scheduling for Prepayments
• Manual tracking of milestone payments

🆕 BONUS: New in 2024 R1+ — Flexible Progress Billing Enhancements

If you're on 2024 R1 or R2, you may also benefit from enhanced billing logic in:

Projects → Progress Billing or Pro Forma Invoicing (Project Accounting)

You could:

• Use a non-project service item tied to phases
• Bill customer using pro forma or AR invoices, pre-shipment

🔧 This does require Projects module but adds scheduling, control, and reporting.

🚀 Recommended Hybrid Process

If you don’t want to buy extra modules:

🔁 Suggested Flow (Minimal Customization)

1. Create SO for customer → Don't ship yet
2. Manually create AR Invoices using Installment Terms (simulate payment schedule)
3. Use workflow conditions or custom validations to:
   • Prevent Shipment until X% of Installment Invoices are paid
4. When ready, ship and do final invoice if needed (even at $0)

You can then report on total billed/paid via GIs.

💡 ERP Pro Tips

💡 For Controllers: Use AR Aging with Installment Detail to track outstanding progress payments by due date
💡 For Sales Ops: Add a custom field to Sales Order to track % Paid or Installment Status
💡 For Admins: Consider adding a custom validation rule to block shipment if not enough has been invoiced or paid

📌 Summary