Order-to-Cash (M4)

The mirror of Procure-to-Pay on the sales side: customer → order → delivery → invoice → payment. Two things make this flow safe — the credit gate runs before confirmation, not after delivery, and COGS is booked per item at real cost, never at guesswork.

Actors: SALES_OPERATOR (orders), WAREHOUSE_OPERATOR (delivery), FINANCE_OPERATOR (invoice/payment).

1. Customer master

Set each customer's credit limit, payment terms (days), and NPWP. The credit limit is enforced in step 3; the terms drive invoice due dates.

2. Sales order

Create the SO with lines (qty & price). Status: DRAFT — no stock reserved, nothing committed.

3. Confirm — the credit gate

fn_check_credit_limit runs before confirmation, inside the RPC:

outstanding AR + open orders + this order  vs.  the customer's limit

• Exceeded → CREDIT_LIMIT_EXCEEDED, the SO stays DRAFT. No exception path — an operator cannot "force it through".
• Passed → CONFIRMED.

Because the check runs at confirmation, a customer over their limit can never accumulate more deliverable orders — the gate is at the door, not at the exit.

4. Delivery order

The warehouse issues stock per line at moving-average cost:

• Partial deliveries allowed → PARTIALLY_DELIVERED → DELIVERED.
• Over-delivery is blocked — you cannot ship more than the confirmed order.
• Stock availability is checked before any cost layer is burned — no negative stock.

5. AR invoice

Issued from a delivery order (3-way match DO ↔ SO). PPN 11% by default. The GL posting is two-sided and per item:

Dr  AR                    (revenue + PPN)
Cr  Revenue
Cr  PPN Keluaran

Dr  COGS          ┐ per item — the moving-average cost
Cr  Inventory     ┘ from the delivery, not the sale price

The COGS entry per item is what makes gross margin on any report truthful.

6. Payment

fn_record_ar_payment auto-allocates FIFO by due date (or an explicit allocation if you prefer):

• posts Dr Cash / Cr AR,
• a surplus stays unallocated on the invoice — overpayment never silently becomes revenue,
• fully-paid invoice → PAID.

7. Returns

A sales return takes stock back at cost basis — never at sale price:

• issues a credit note: Dr Sales Return / Dr PPN / Cr AR + Dr Inventory / Cr COGS,
• reduces the customer's AR balance.

Because stock returns at cost, a returned item re-enters inventory at what it cost you — a high-margin product cannot inflate your inventory value on the way back in.

Guards recap

What's next

• Procure-to-Pay — the mirror flow on the buying side.
• Month-End Close — where these invoices land at close.
• Deep-dive: docs/USER_FLOWS.md §5 in the repository.