The inventory cash calendar: knowing when every PO hits your bank
Build an inventory cash flow calendar that maps every PO payment, freight bill, and duty to the week it leaves your bank — weeks before it happens.
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September's P&L says you made money. Your bank balance on November 10 says you cannot yet cut the balance check for the phone-stand container that just cleared ship confirmation. Both statements are correct, and the gap between them is not a mystery — it's a scheduling problem.
A dozen weeks of PO payments, freight invoices, and duty bills hit specific calendar weeks, and almost nobody writes them down. The inventory cash calendar does exactly that: eleven weeks, four inputs, about an hour, and the week your balance bottoms out becomes visible while there's still time to move it.
Why the cash date isn't the order date
The order date is only the first domino. Between signing a PO and the last dollar leaving, a typical imported order has four or five separate payment events, each with its own trigger:
- Deposit — often 30% or 50% at order placement
- Balance — the remainder, due before shipment, on delivery, or on terms
- Freight — the forwarder's invoice, usually on documents or arrival
- Duty and entry fees — estimated at booking, billed at customs entry
- Receiving and handling — your 3PL's invoice after the goods land
A $16,000 PO is therefore not one $16,000 event on one date. It's $4,800 the day you sign (a 30% deposit, illustrative), $11,200 six weeks later, $2,600 of freight a week after that, and $1,300 of estimated duty behind it. When three POs overlap, their events interleave — that's the pileup this calendar exists to expose.
(If you want the metric that summarizes this whole lag — how many days a dollar is locked in stock — that's the cash conversion cycle, and it owns the explanation. This article builds the forward-looking artifact; that one explains the number.)
The four inputs
- Open POs with their payment terms. Every PO in flight, with deposit percentage, balance trigger, and invoice dates. If your POs live in a proper lifecycle from draft to filed, this is a ten-minute export; if they live in your inbox, budget the hour. If you don't yet have the open-PO portfolio view, the purchase order tracker spreadsheet builds it — the tracker feeds the open-PO side of this calendar with one row per order, its value, and its expected date.
- Measured lead times. The arrival column is only as honest as your lead-time number. Use your own history, not the supplier's quote — measured supplier lead time is the difference between an arrival date and a wish.
- Supplier terms. Net-30 from invoice date moves the balance event a full month later than "before ship." The mechanics of what those terms do to your cash are covered in net 30 payment terms; here they're just columns with dates.
- A conservative receipts forecast. Your expected weekly cash-in, discounted. Pick your own haircut — the size matters less than holding it consistently, so the calendar errs pessimistic.
The calendar, built
SnapStand, a phone-stand and desk-accessory importer (all figures illustrative). Opening bank balance: $19,000. Conservative receipts plan: $6,200 per week. Open POs and their payment events:
| Event | Amount | Trigger | Week of |
|---|---|---|---|
| PO-143 deposit (50% of $12,500) | $6,250 | At order | Nov 3 |
| PO-141 balance (70% of $16,000) | $11,200 | Before ship confirmation | Nov 10 |
| PO-141 freight | $2,600 | Forwarder invoice on documents | Nov 17 |
| PO-141 duty (estimated) | $1,300 | Customs entry | Nov 17 |
| Domestic accessories PO (net-15) | $1,900 | Invoice terms | Nov 24 |
| 3PL receiving overage | $1,200 | After container lands | Nov 24 |
| PO-143 balance (50%) | $6,250 | At pickup | Dec 8 |
| PO-144 deposit (40% of $21,000) | $8,400 | At order | Dec 15 |
| PO-144 balance (60%) | $12,600 | At ship | Jan 5 |
Note what's absent: PO-141's $4,800 deposit, paid back in September when the PO was signed. The calendar starts where your open commitments are, not where your past payments were.
Now roll it forward week by week:
| Week of | Money out | Money in | Net | Balance |
|---|---|---|---|---|
| Oct 27 | $0 | $6,200 | +$6,200 | $25,200 |
| Nov 3 | $6,250 | $6,200 | −$50 | $25,150 |
| Nov 10 | $11,200 | $6,200 | −$5,000 | $20,150 |
| Nov 17 | $3,900 | $6,200 | +$2,300 | $22,450 |
| Nov 24 | $3,100 | $6,200 | +$3,100 | $25,550 |
| Dec 1 | $0 | $6,200 | +$6,200 | $31,750 |
| Dec 8 | $6,250 | $6,200 | −$50 | $31,700 |
| Dec 15 | $8,400 | $6,200 | −$2,200 | $29,500 |
| Dec 22 | $0 | $6,200 | +$6,200 | $35,700 |
| Dec 29 | $0 | $6,200 | +$6,200 | $41,900 |
| Jan 5 | $12,600 | $6,200 | −$6,400 | $35,500 |
The floor is $20,150 in the week of November 10, and the cluster is visible: $21,350 leaves the account across the three weeks of November 3–17. Seen six weeks out, that's a planning problem. Seen on November 8, it's a crisis with a wire deadline.
What the calendar lets you change
With the dip visible in October, the levers are ordinary:
- Move an order. Shift PO-143 from a November 3 order date to November 17 and its $6,250 deposit slides two weeks: the November 10 floor rises from $20,150 to $22,450, and the pinch week now shares the month with nothing else. Same goods, same supplier, same total — two weeks later.
- Split a payment. Ask PO-141's supplier for a 50/50 split instead of 70/30 and $3,200 moves from the ship trigger to pickup. Worth one email; the calendar tells you exactly how much it's worth.
- Use terms where they exist. Any balance that can ride net-30 from invoice leaves the cluster entirely — though the terms themselves have costs and mechanics worth reading before you ask.
- Schedule non-stock spend away from cluster weeks. The trade-show deposit, the website rebuild, the estimated tax payment — everything discretionary moves to the weeks with positive net.
- Know when it's a financing question. If no arrangement of timing fixes the floor, the gap is real, not schedulable — that's a borrowing conversation, and the options live elsewhere.
Run one sensitivity line while you're in the sheet: at $5,000 per week of receipts instead of $6,200, the November 10 week bottoms at $16,550 — three weeks of the haircut compounding before the dip. If that number is below your comfort line, the conservative case, not the base case, should drive the decision.
Three disciplines that keep the calendar true
Every signed PO creates its payment rows the same day. Not when the invoice arrives — by then the calendar has already lied to you for weeks. Deposit row, balance row, freight row, duty row, dated and committed.
Arrival-triggered events use measured lead times. The balance-on-ship event is dated from your own history of this supplier, because the quoted number is the one input guaranteed to be optimistic.
The receipts haircut stays fixed. The temptation after three good months is to quietly raise the weekly cash-in. The calendar's entire value is that it errs pessimistic; raise the haircut deliberately, at a month boundary, in writing to yourself.
What the spreadsheet can and can't do
Shopify's native purchase orders record the order date and expected arrival, which covers the goods side of the calendar (Shopify Help Center, accessed November 2026) — but supplier payment events are not something the admin schedules, so the money-out column remains a spreadsheet job.
That's also where our own tooling honestly sits: InventoryX's planned Monday Buying List is intended to produce the order-by dates that populate the left edge of this calendar, and V1 deliberately stops there — it doesn't track payment terms or move money. The calendar above is yours to keep.
Common questions
How do I forecast cash flow for inventory purchases? List every open PO, break each into its payment events — deposit, balance, freight, duty — with trigger dates, then roll them week by week against a conservative receipts forecast. The worked calendar above takes about an hour to build and eleven columns to maintain. Update it the day any PO is signed or any date slips.
When does a PO hit my cash — order date, ship date, or arrival? Whenever its payment events say. A 30% deposit hits at order, a 70% balance may hit before ship, freight bills on documents, duty at entry. The order date matters because it starts the clock, but the bank feels the dates in the payment-events table, not the order date itself.
How do deposit terms like 30/70 change my cash calendar? They split one event into two, weeks apart. On a $16,000 PO, $4,800 leaves at signing and $11,200 leaves at the ship trigger — which your measured lead time dates. That second event is the one that piles up when orders overlap, which is why the calendar surfaces it six weeks early rather than at the wire.
What's a buying budget calendar? The same artifact viewed from the buying side: instead of asking "when does money leave," it asks "what can I commit to buying, in which week, without breaching a floor balance." Build the payment calendar first; the buying budget is its mirror — the white space between cluster weeks.
How far ahead should I plan inventory payments? One full replenishment cycle plus your longest terms — for an ocean-imported catalog, twelve weeks covers a measured lead time, a balance trigger, and a net-30 tail. Rebuild or extend the sheet whenever the furthest open event approaches the edge of the window.
Next step
Open a sheet today and enter just your open POs' payment events for the next eleven weeks — don't reorganize anything else first. Put the floor week on your wall. Then adopt the one-line rule that keeps the calendar honest: no PO gets signed until its deposit, balance, and freight rows exist with dates. When you want the metric behind all this timing — how long a dollar stays locked in stock — read the cash conversion cycle computed on real store numbers.