@zenuinebit/supplier-ledger

Payables for one supplier: statement, open bills with payment matching, ageing, a due list, payment planning with a limited budget, and early-payment discounts. Built on @zenuinebit/customer-ledger but speaking the language of payables. Amounts are positive integers in minor units; dates are "YYYY-MM-DD".

import { statement, openBills, balance, ageing, dueList, paymentPlan, earlyPaymentOffers, type SupplierTxn } from "@zenuinebit/supplier-ledger";

const txns: SupplierTxn[] = [
  { id: "B1", date: "2025-03-01", type: "bill", amount: 100_000, dueDate: "2025-03-31",
    terms: { percent: 2, withinDays: 10 } },                                           // "2/10 net 30"
  { id: "B2", date: "2025-03-05", type: "bill", amount: 50_000, dueDate: "2025-04-04" },
  { id: "T1", date: "2025-03-20", type: "tds", amount: 2_000, appliesTo: "B1" },      // TDS you withheld
  { id: "P1", date: "2025-03-20", type: "payment", amount: 98_000, appliesTo: "B1" },
];

balance(txns, "2025-03-25");               // what you owe: 50_000
openBills(txns, "2025-04-10");             // each bill: paid, balance, status, daysOverdue; plus owed, overdue, advance
ageing(txns, "2025-04-10");                // Current, 1-30, 31-60, 61-90, 90+
dueList(txns, "2025-03-25", 7);            // { overdue, dueSoon, totals }

// Which bills should this week's cash cover?
paymentPlan(txns, "2025-04-10", { budget: 30_000, strategy: "earliest-due" });
// { payments: [{ id, pay, partial }], total, remainingBudget, unpaid }

// Early-payment discounts still on offer
earlyPaymentOffers(txns, "2025-03-05");
// [{ billId: "B1", deadline: "2025-03-11", discount: 2000, payNow: 98000, impliedAnnualPercent: 37.2 }]

Transaction types: increase what you owe: opening, bill, extra-charge. Reduce it: payment, credit-note (issued by the supplier), purchase-return, tds (withheld, to be paid to the government), discount (early-payment discount taken). A reducing entry can name its bill with appliesTo; otherwise the oldest due bill is paid first.

Good to know

• A positive balance means you owe the supplier; a negative one means they hold an advance from you (advance in the results).
• To take an early-payment discount, post a discount for the offer's discount and a payment for payNow, both with appliesTo the bill.
• impliedAnnualPercent is what paying early earns as a yearly rate (a "2/10 net 30" discount is about 37%). It is null if the bill is not due after the discount deadline.
• paymentPlan only plans. By default it covers what is due today or overdue; pass dueWithinDays to include bills falling due soon, allowPartial: false to avoid part payments, and a strategy of earliest-due, smallest-first or largest-first.
• Pair with @zenuinebit/tds-calc to work out the TDS to withhold, and @zenuinebit/purchase-gst for input credit.

Not included: several suppliers in one call (keep a list per supplier), storage, remittance advice, and foreign currency.