Lumina

ASNAdvanced Shipping Notice

A supplier's notification of what has actually been shipped and when it will arrive — the message that tells you the contents and timing of an inbound shipment before it lands.

By Oana Bradulet

An ASN — Advanced Shipping Notice — is the message a supplier sends to tell you what they have actually shipped against your order, and when it's expected to arrive. It's the bridge between "we placed a purchase order" and "stock turned up at the dock". In EDI environments it's the 856 transaction; for smaller suppliers it might be a structured email or a spreadsheet. The format matters less than the fact of it.

The ASN is often the first moment you learn that what's coming differs from what you ordered. A PO for 1,000 units comes back as an ASN for 940 because the supplier was short on one colourway. A three-line order ships as two lines now and one to follow. The expected arrival has slipped two weeks. None of this is unusual — and without an ASN you'd find out only at goods-in, far too late to react.

What an ASN contains

A useful ASN tells you, at minimum:

  • Which PO it relates to.
  • What's actually in the shipment — line by line, the quantities being shipped (which may differ from the ordered quantities).
  • How it's packed — cartons, pallets, often tying through to the packing list.
  • When it shipped and when it's expected — the dates that turn an order into trackable in-transit inventory.
  • References — container or shipment IDs, carrier, sometimes the bill of lading reference.

The richer the ASN, the less you're guessing between order and arrival.

Why the shipped quantity differs from the PO

Treat the ordered quantity and the shipped quantity as two different numbers, because they routinely are:

  • Short shipment — the supplier couldn't complete the full order in time and shipped what was ready.
  • Split shipment — part now, part to follow, often when one line needs more production time.
  • Over-shipment — the supplier produced slightly over and shipped the lot, common where MOQ rounding applies.
  • Substitution — a swapped size curve or colourway when the original wasn't available.

The PO is your intent. The ASN is reality. Planning against the PO when the ASN says something different is how you build a stock projection that arrival contradicts — better to update the plan the moment the ASN lands.

Why the ASN matters for planning

The ASN is the earliest reliable signal you have about an inbound shipment, and earlier signals are worth real money:

  • Receiving prep. The warehouse knows what's coming and can resource goods-in rather than reacting to a surprise container.
  • Stock projection accuracy. Your forward cover should reflect what's shipping, not what was ordered three months ago.
  • Exception handling. A short shipment spotted on the ASN gives you weeks to decide — reorder, expedite, or accept the gap — instead of discovering it at receipt.
  • Discrepancy resolution. Matching ASN to PO and then receipt to ASN is the spine of clean three-way reconciliation.

ASN vs. the documents around it

The ASN is easy to confuse with its neighbours:

  • PO — your order, your intent, sent before anything ships.
  • ASN — the supplier's statement of what actually shipped and when, sent as goods leave.
  • Packing list — the carton-level detail of the physical contents, used at goods-in.
  • Invoice — the request for payment, reconciled against what was ordered and received.

They overlap in content but serve different moments. The ASN's job is to give you advance notice — the clue is in the name.

Common mistakes

  • →Planning against the PO quantity and ignoring the ASN. The PO is intent; the ASN is what actually shipped — short, split, and over-shipments mean the two regularly disagree.
  • →Treating the ASN as paperwork rather than a planning signal. It's the earliest reliable read on what's inbound and when, and reacting to it early is far cheaper than reacting at goods-in.
  • →Not reconciling ASN to PO and receipt to ASN. Skipping the three-way match lets discrepancies hide until they surface as missing stock or invoice disputes.
  • →Assuming every supplier sends a usable ASN. Smaller suppliers may send a thin email; it's worth specifying what you need — PO reference, line quantities, and an ETA — so the notice is actually actionable.

How Lumina handles ASNs for scaling brands

Lumina tracks your inbound shipments against the PO — quantities and dates — so the stock projection updates the moment what's coming differs from what you ordered.

Frequently asked questions

What is an ASN?
An ASN (Advanced Shipping Notice) is a supplier's notification of what they have actually shipped against your order and when it's expected to arrive. In EDI it's the 856 transaction; for smaller suppliers it may be a structured email or spreadsheet. It's the bridge between placing a PO and stock arriving at the dock.
What's the difference between an ASN and a packing list?
An ASN is sent in advance, as goods leave the supplier, to give you notice of contents and timing. A packing list is the carton-level detail of the physical shipment, used at goods-in to check what's actually in each box. They overlap in content but serve different moments.
Why does the ASN quantity differ from the PO?
Because the PO is your intent and the ASN is reality. Suppliers short-ship when they can't complete an order in time, split shipments across two sailings, over-ship due to MOQ rounding, or substitute a colourway or size curve. The ASN is often the first place you learn the shipped quantity isn't the ordered quantity.
Why does an ASN matter for planning?
It's the earliest reliable signal about an inbound shipment. It lets the warehouse prep receiving, keeps your forward cover based on what's actually shipping rather than what was ordered months ago, and gives you weeks of warning on a short shipment so you can reorder, expedite, or accept the gap before it becomes a stockout.
Do all suppliers send an ASN?
Not consistently. Large suppliers in EDI relationships send a standard 856; smaller suppliers may send a thin email or nothing at all. It's worth specifying what you need — the PO reference, line-level shipped quantities, and an expected arrival date — so the notice is actually actionable rather than just confirmation that something is on its way.

Related terms

Purchase order— Purchase Order (PO)

A formal document that a buyer issues to a supplier specifying what to ship, in what quantity, at what price, and when.

Packing list

The document itemising what's physically in each carton and pallet of a shipment — the reference your warehouse checks goods in against, and the partner document to the commercial invoice.

In-transit inventory

Inventory you own but isn't at your location yet — moving between supplier and warehouse, or between two warehouses you control.

Lead time

The total time between placing an order with a supplier and having the goods available to sell.

Bill of lading— Bill of Lading (B/L)

The shipping document that acts as receipt for the goods, evidence of the carriage contract, and — crucially — the document of title that controls who can collect the cargo at destination.