Nearly every box you open from an online store has one: a plain sheet of paper listing what should be inside. That is the packing slip. It exists because the person who packed the box and the person who opens it never meet, and something has to carry the order across that gap.
The confusion that sends most people searching for this term is not what a packing slip is. It is which of the four documents attached to a shipment is the packing slip, and which is the invoice, the label, or the customs paperwork. So this guide defines the slip, then puts all four side by side.
What goes on a packing slip
There is no standard form. What ends up on the sheet is whatever the seller's system prints, and in practice that settles into a short list:
- The order number. The single most useful field on the page. It is what customer service, the warehouse and the returns desk all search on.
- Seller and recipient details. The ship-to address, often the bill-to address as well, and the seller's name and contact.
- Each item, with a SKU. A product name on its own is ambiguous once you have variants. The SKU is what the packer scans and what the recipient quotes back to you when something is wrong.
- Quantity shipped, against quantity ordered. These are two different numbers whenever an order ships in parts. Shopify, for example, exposes both line_item.quantity and line_item.shipping_quantity to its packing slip template, plus a flag for whether every line in the order is in this shipment.
- Anything still to come. A line for backordered or unfulfilled items, so a short box reads as expected rather than as an error. See what a backorder is.
- Carton information, on freight and wholesale shipments. Carton count, carton numbering, weights and dimensions. Consumer parcels rarely carry these; a pallet going to a distribution center usually must.
- Returns instructions. Optional, and on consumer parcels the most valuable thing you can add, because the slip is the one piece of paper the customer has kept.
What is normally absent is money. No unit prices, no tax, no shipping charge, no balance due. That is the invoice's job, and the next section explains why the separation is deliberate.
Packing slip vs invoice vs shipping label vs commercial invoice
These four documents can all ride on the same shipment, and they answer four different questions: what is in the box, what is owed, where the box goes, and what customs needs to know.
| Packing slip | Invoice | Shipping label | Commercial invoice | |
|---|---|---|---|---|
| What it is for | Listing the contents of this shipment so they can be checked | Requesting payment for the order | Telling the carrier where the parcel goes and letting it be scanned | Declaring the goods, their value and origin to customs |
| Who reads it | The packer, and the person unpacking the box | The buyer, and both sides' accounting | The carrier and its sorting equipment | Customs authorities, and the broker clearing the entry |
| Does it show prices | Usually no | Yes, that is the point | No | Yes, values are mandatory |
| Where it travels | Inside the box, or in a pouch on the outside | Usually sent separately, by email or through an accounting system | Affixed to the outside of the parcel | In a document pouch on the outside, or filed electronically with the carrier |
| Is it required | No general legal requirement for a domestic parcel; often required by contract | Not by shipping law, but required commercially and for tax records | Yes, in practice nothing moves without one | Generally required for imports into the US, with limited exemptions |
A fifth document turns up on freight rather than parcel: the bill of lading. It is the carrier's receipt and the contract of carriage, and for interstate motor carriage 49 CFR 373.101 requires the carrier to issue one showing the consignor and consignee, the origin and destination, the number of packages, a description of the freight and, where it affects rating, the weight or volume. A packing slip describes what is in the cartons; the bill of lading governs the move of the cartons themselves. If a shipment goes out on a pallet, you will have both.
Why prices are usually left off
Omitting prices is not an oversight. Three situations make it the safer default:
- Gifts. The buyer and the recipient are different people, and printing the amount paid on a sheet inside the box is a reliable way to spoil the moment.
- Dropshipping and white label. The box ships from your warehouse but carries another brand's order. A price sheet from you exposes the margin in between.
- Wholesale and B2B. The person receiving the pallet at a store or a distribution center is a receiving clerk counting units, not the accounts payable team. Pricing goes to accounts payable, often as an EDI invoice, not into the carton.
The pattern is consistent enough that fulfillment software tends not to offer prices at all. Shopify's packing slip variable reference, for instance, documents store, order, customer, address and line item fields, with no price or order total variable among them.
Inside the box or outside it
Both are normal, and the choice follows from who has to read the slip first.
Inside, on top of the contents. The convention for direct-to-consumer parcels. The customer opens the box, the slip is the first thing they see, and it doubles as the returns reference. It also stays dry and cannot be torn off in transit.
Outside, in a clear adhesive pouch. The convention for wholesale, retail and freight. A pouch marked packing list enclosed sits next to the carton label so a receiving clerk can check the shipment in against the purchase order without opening it. On international shipments the same style of pouch carries the customs paperwork.
One practical note for retail: if a carton is going into a retailer's network, the pouch position is often specified, not suggested. Put it where the routing guide says, not where it fits.
Is a packing slip legally required?
For a domestic parcel in the United States, no general rule requires one. The paperwork the law does mandate is a different set of documents, and the contrast is the clearest way to see it:
- Interstate motor freight. The carrier must issue a receipt or bill of lading under 49 CFR 373.101. That is a duty on the carrier, and it is not a packing slip.
- Imports into the US. Under 19 CFR 141.83, a commercial invoice must generally be filed for each shipment of imported merchandise, subject to the exemptions the regulation lists. 19 CFR 141.86 sets out what it has to contain, including a description of the goods, quantities, values, all charges such as freight, insurance and packing, and the country of origin. It also requires that each invoice state in adequate detail what is in each individual package, which is exactly the function a packing list performs, and why exporters usually attach one.
- International mail. USPS requires a customs declaration on international items, with a narrow exception it states for First-Class Mail International under 15.994 oz containing only nonnegotiable documents or correspondence. Check the current form against the USPS customs forms page before you ship, because form numbers change.
- Delayed orders. Noting a backorder on the slip is helpful, but it is not the notice the law asks for. The FTC Mail, Internet, or Telephone Order Merchandise Rule at 16 CFR 435.2 requires a seller who cannot ship on time to offer the buyer a choice between consenting to the delay and cancelling for a prompt refund.
So the honest answer is that packing slip requirements are almost always contractual. A marketplace, a retailer or a brand you fulfill for can make one mandatory, and then it is mandatory for you. Nothing in federal shipping law makes it so on its own. None of the above is legal advice, and an attorney or a licensed customs broker should confirm anything you intend to rely on. We are neither.
What the warehouse actually uses it for
On the pick line, the slip is not a courtesy for the customer. It is the work order. In a paper-driven operation the picker carries it around the shelves and it lists the items in pick sequence; in a scan-driven operation the pick happens on a handheld and the slip prints at the pack bench as the document the packer checks the finished box against.
Either way it is the last chance to catch a mispick before the box is taped. Packers compare the units in the carton to the lines on the sheet, confirm the count, and only then print the label. That check is the reason the slip lists quantity shipped rather than quantity ordered: the packer needs to know what should be in this box, not what the customer bought in total. More on the sequence in our guide to pick and pack fulfillment.
The slip is also the document a return arrives with. When a customer sends something back, the order number on the sheet is what ties the parcel on the returns bench to the order in the system.
What a retailer's routing guide can demand
Ship to a large retailer and the packing slip stops being your decision. The routing guide is the document that says how their vendors must ship, and slip requirements are a standard section of it. Guides differ, most live behind a vendor portal, and the only version that counts is the current one for your account, so read yours rather than a summary. The kinds of things they commonly specify:
- One packing list per purchase order, keyed to that PO number.
- Item identifiers in the retailer's own terms, which normally means a UPC or GTIN plus their internal item number, not just your SKU.
- Quantities expressed in consumer selling units rather than in cases.
- A fixed physical position for the document, typically a pouch on the outside of a nominated carton next to the carton label.
- An electronic counterpart, since the paper slip does not replace the advance ship notice the retailer expects by EDI before the truck arrives.
Getting these wrong is expensive in a specific way: retailers enforce routing guides with chargebacks, deductions taken off your invoice for non-compliance. A slip in the wrong place can cost real money on an otherwise perfect shipment. If any of these terms are unfamiliar, our logistics glossary defines them.
Getting it right without thinking about it again
A packing slip is a small document with one job: making the contents of a box checkable by someone who was not there when it was packed. Decide the template once, decide whether prices appear, decide inside or outside, honor whatever a retailer's routing guide overrides, and then let it run.
If a 3PL packs your orders, the slip prints from your order data on a template you approve, which is worth reviewing at onboarding rather than discovering later. We run one warehouse, in Austin, Texas, and set this up with brands as part of pick and pack onboarding.