GS1-128 Labels: How the SSCC Label on Cartons and Pallets Works

An SSCC label is the GS1-128 shipping label, formerly called a UCC-128 label, that retailers require on cartons and pallets shipped to their distribution centers. Its barcode holds an 18-digit Serial Shipping Container Code (SSCC) that identifies that one box or pallet and ties it to the advance ship notice (ASN), so the DC can receive the whole unit with a single scan instead of opening it. Get the label wrong and the retailer charges you for the cartons it has to receive by hand. Brands new to retail can ship those cases and pallets from the same stock that feeds their ecommerce fulfillment.

What is an SSCC label?

SSCC is the GS1 standard number for a logistic unit, meaning anything you ship as one piece: a carton, a tote or a built pallet. Each unit gets its own number, and no two units you ship should ever share one.

The number is always 18 digits, printed as a GS1-128 barcode with a human-readable line underneath. Walmart's April 2026 Supply Chain Packaging Guide breaks it into five parts:

1. Application identifier (00). Two digits printed in front of the SSCC that tell the scanner a shipping container code follows. They sit outside the 18.
2. Extension digit. One digit, 0 to 9, that adds numbering capacity. The company assigning the SSCC decides how to use it.
3. GS1 company prefix. The number your company licenses from GS1 US. It identifies who built or owns the unit.
4. Serial reference. The serial number you assign to each carton or pallet. Walmart's guide suggests the simplest method: count up, one unit at a time.
5. Check digit. The last digit, calculated from the other 17 with the GS1 formula, so a misread barcode fails instead of scanning as the wrong carton.

GS1 US prints a sample in its standards guide: (00)614141123456789017. The prefix has to be yours or your logistics provider's. Walmart's guide names the physical builder or the brand owner as the company that allocates the SSCC and bans suppliers from using Walmart's own prefix. The GS1 US prefix behind your UPCs also builds case and pallet numbers.

Ulta's April 2026 supply chain guide bars reusing an SSCC for three years, and other retailers set their own windows. A label template that resets its counter every morning produces duplicates the next day.

What is a GS1-128 label, and is it the same as a UCC-128 label?

Yes. GS1-128 and UCC-128 name the same label. Walmart's guide spells out the history: the GS1-128 barcode was formerly known as UCC/EAN-128. Older vendor manuals, such as Scheels' 2016 guide, still say UCC-128 throughout.

What's on a UCC-128 label, zone by zone

Shipping labels are laid out in zones, each block holding one kind of information. The clearest published example is in Amazon's 2016 North American Vendor Transportation Manual. Newer Vendor Central rules have replaced that manual, but its sample label still shows each zone plainly:

• Zone A, ship from. Your company name and the address the freight leaves from.
• Zone B, ship to. The DC's name and full address, often with the retailer's DC number.
• Zone C, carrier routing barcode. A barcode the carrier uses to route the freight.
• Zone D, carrier. Carrier name, PRO number and bill of lading (BOL) number.
• Zone E, purchase order. The PO number, often as a barcode, the UPC or "mixed SKUs," the unit quantity and the carton count, such as "carton 1 of 10."
• Zone F, SSCC. The GS1-128 barcode with the 18-digit SSCC and its readable digits, at the bottom of the label.

Amazon's 2016 manual made zones A, B, E and F mandatory and called C and D strongly recommended. Walmart's 2026 guide sets a lower floor: the SSCC barcode is the only required element. Ship-from and ship-to addresses, the Walmart DC number, department number, PO type, the 10-digit PO number, carrier, BOL and PRO are recommended, and the recommended label size is 4 by 6 inches.

Your retailer's version lives in its routing guide and vendor manual. Read the label page before you print anything, because extra fields, such as Walmart's DC and department numbers, change from one retailer to the next.

Why the SSCC label has to match the ASN

The ASN, sent as an EDI 856, tells the DC what's on the truck before it arrives. Each carton or pallet SSCC on the ASN points to its contents: the PO, the item, the quantity and any dates.

Amazon's 2016 manual calls this license-plate receive. The DC scans the SSCC on the carton, its system finds that SSCC in the ASN, and every item in the carton gets received without anyone scanning each unit. Walmart's 2026 guide requires the same match: the SSCC on the label has to equal the SSCC in the ASN's "MAN" segment.

Building the ASN, its hierarchy and its timing is covered in our guide to the EDI 856 advance ship notice.

The safest way to keep them equal is to create both from one scan. When the warehouse prints the label at pack-out and the ASN is built from the SSCCs scanned onto the pallet, the two can't drift apart. When someone builds the ASN from the PO and prints labels separately, every short carton or swapped label becomes a mismatch.

What the DC does when the label and ASN don't match

A carton the DC can't match goes to manual receiving: someone opens it, counts it and keys it in. The retailer bills you for that labor, usually as a chargeback taken out of your invoice payment.

What published vendor manuals charge:

• Scheels (2016 guide): $25 per carton that's missing a UCC-128 label or has a label on the wrong carton, and $25 per incorrect ASN document.
• Sephora (January 2026 routing guide): $5 per carton for a missing or nonfunctional GS1-128 label, and $5 per carton when contents differ from the ASN or label, with a $150 minimum on each.
• francesca's (December 2025 compliance agreement): 10% of the entire invoice for improper packaging or pallet builds, plus the cost to correct, and another 10% of the invoice for failing its EDI requirements.
• Amazon (2016 manual, now replaced): $5 per carton with no carton content label.

A wrong prefix or a repeating counter in your label template hits every carton on every shipment until someone fixes it. A 600-carton PO at Scheels' $25 rate is $15,000 in fees on one shipment. Sorting those deductions and disputing the wrong ones is covered in our guide to vendor chargebacks and how to dispute them.

Carton label: where it goes on a case

A label with perfect data still fails if the scanner can't find it or read it.

Walmart's rules for an individual case:

• Put the label left of center on the longest side of the case.
• If the case is too short, put it on top.
• Print-and-apply barcodes must reach ANSI grade B or better.
• The GS1-128 barcode must be at least 3 inches long and 0.75 inch high, with at least 0.25 inch of white space on each side.
• The label must lie flat, and the barcode must scan through any plastic film and never sit under a seam.

Scheels' 2016 vendor guide adds three rules. The label goes on crease free so the SSCC scans. It sits next to the other shipping labels on the box. When the shipping carton is also the retail package, the label goes on a side the shopper won't see.

Retailers also differ on which cartons need an SSCC at all. Amazon's 2016 manual wanted one on every carton. Scheels wanted one on each box or pallet. Walmart requires case-level SSCC labels only in specific programs, such as direct store delivery, small parcel and consolidation shipments, and asks for the SSCC on the pallet for regular palletized freight. Follow the guide for the retailer on the PO.

Pallet label: placement and contents

A pallet label carries its own SSCC, separate from the SSCCs on the cartons stacked on it. In Walmart's samples, a single-SKU pallet label names the item and the case count, and a mixed pallet label says MIXED PALLET in large type.

Walmart's 2026 guide sets these rules for domestic pallets:

• Labels go on at least two adjacent sides of the pallet, preferably in the upper right corner.
• Best practice is to place each label between layers of stretch wrap, so it stays readable and attached.
• The SSCC-18 barcode is the required format on every pallet label.
• A mixed-item pallet label may not carry the orderable case GTIN.
• A pallet SSCC doesn't replace the GTIN barcode each case still needs.

Kroger's compliance policies make the pallet number count twice: the pallet SSCC in the ASN must match the GS1-128 label on the pallet.

Master carton label

A master carton is the outer shipping case that holds inner packs or individual units. It's the unit the retailer receives, so the shipping label and its SSCC go on the master carton, not on the inner packs inside it.

That creates two barcode layers. Inner packs keep their own GTIN or UPC barcodes for the shelf or the DC's pick line. The master carton carries the SSCC that ties it to the ASN, plus the case GTIN when the retailer asks for one. Trouble starts when an inner-pack barcode shows on the outside of the master carton. The DC scanner reads the inner pack instead of the case, and the count no longer matches the ASN. Amazon charges that as a case-pack defect. Keep inner-pack barcodes inside, and keep the master carton label the only GS1-128 shipping label on the outside.

How to get carton and pallet labels right before the first PO

1. Get the retailer's label spec. Pull the label pages, and any sample label, from each retailer's vendor manual.
2. License a GS1 company prefix. If your UPCs came from GS1 US, use the same prefix. If your 3PL assigns SSCCs under its own prefix, confirm the retailer accepts that.
3. Set up serials that never repeat. One counter per prefix, never reset, so no SSCC comes back inside the retailer's reuse window.
4. Print a sample and get it checked. Walmart's labeling team reviews emailed sample labels for required fields and a barcode that scans in the right format. It doesn't check that your data is correct, so verify the PO, address and counts yourself.
5. Photograph labeled cartons and pallets before loading. Those photos are your evidence when a label chargeback is wrong.

How KSP labels retail cartons and pallets

KSP ships retail orders from the same inventory as a brand's DTC parcels. The retailer's routing guide goes into the warehouse SOP before the first PO ships, and the first labels are checked against the guide. On every retail order, each case or unit barcode is scanned against the order, and a mismatch stops the workflow until it's fixed. UCC-128 carton labels are verified before cartons close. The ASN goes out through SPS Commerce before the truck leaves, built from what was scanned onto the pallet, so the ASN lists what's on the truck.

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