For decades, the standard carton barcode was the ITF-14. It did one job: encode the GTIN and identify the product. Simple, reliable, and widely used across the grocery supply chain.
That's no longer enough. Under FSMA 204 and Walmart's food traceability requirements, carton barcodes now need to carry lot-level data. That means which lot the product came from, when it was packed, and when it expires. The GS1-128 barcode is how that data gets onto the case.
This post covers what Walmart requires at the carton level, why GS1-128 is now required, and what suppliers need to do.
For complete requirements, go to Walmart's current Supply Chain Requirements.
A GS1-128 barcode is a linear barcode that uses Application Identifiers (AIs) to encode multiple pieces of data within a single barcode symbol. Unlike the ITF-14, which typically contains only a product identifier, a GS1-128 can include additional supply chain and traceability data such as:
When a carton labeled with a GS1-128 barcode is scanned at a Walmart distribution center, all of this information can be captured automatically in a single scan — without manual data entry. This is what enables efficient lot-level traceability and supports compliance with FSMA 204 requirements at scale.
Walmart requires case-level barcodes capable of carrying traceability data for all food and beverage items — most commonly implemented using GS1-128. For products on the FDA's Food Traceability List (FTL), those barcodes must carry lot number and date data, not just the GTIN.
A compliant GS1-128 carton label must meet four requirements:
All four have to work together. Correct data on a poorly printed label fails. A well-printed label in the wrong location gets missed. Consistency across all four is what keeps cartons moving through receiving.
A compliant GS1-128 carton label carries three data elements — encoded in sequence using Application Identifiers:
The human-readable text printed below or alongside the barcode should include the lot number and date. Walmart requires a minimum font size of 1/2" (48pt) for that information on the case.
One critical detail: the lot number is a variable-length field. When followed by additional data, it requires a hidden character called an FNC1 separator — this tells the scanner where the lot number ends. Without it, the data merges into an unreadable string. The barcode fails silently. This is one of the most common GS1-128 implementation errors.
Walmart's GS1-128 requirements are not one-size-fits-all. Each food department has its own required Application Identifiers based on product type and traceability needs. (01) GTIN and (10) Lot are required across all food formats. The date AI varies by department — harvest date for produce and floral, best by for eggs, seafood, and bakery, scale-by for meat and poultry.
All dates encoded as YYMMDD. AI (10) lot number requires an FNC1 separator when not the final field in the barcode. Floral example sourced from Walmart Supply Chain Standards p. 157.
The barcode on the carton is only half of the equation. Walmart also requires an Advanced Ship Notice (ASN). This is an electronic record transmitted before the shipment arrives. It must contain the same lot numbers, dates, and product identifiers that are on the carton labels.
When cartons arrive at a Walmart DC, the system validates each barcode scan against the ASN in real time. If the lot number on the barcode is LOT4821 and the ASN shows LOT4821-B, that's a mismatch. The carton is flagged for manual handling regardless of how cleanly the barcode scanned.
Barcode data and ASN data must come from the same source — consistently, across every facility, shift, and production run. This is a systems alignment issue as much as a labeling issue.
Walmart tracks barcode and labeling performance through its Supplier Quality Excellence Program (SQEP). When cartons fail at receiving — bad scan, missing data, ASN mismatch — those events are recorded and tied to supplier performance.
SQEP defects accumulate over time. What starts as a labeling inconsistency becomes a pattern. Once that pattern is visible, Walmart may require suppliers to offset the costs incurred. The financial impact compounds quickly when the same problem appears across multiple shipments.
The most effective way to stay out of trouble: verify before cartons leave your facility. A barcode that looks fine may still carry formatting errors that only surface inside Walmart's receiving system. Verification catches them before they become a supplier performance issue.
Meeting Walmart's GS1-128 carton requirements comes down to four things:
Most compliance failures don't come from not knowing the requirements. They come from process gaps — places where data, systems, and physical execution aren't fully connected. Closing those gaps is where the work is.
Getting a carton barcode right isn't just a labeling task. It's the point where FSMA 204 traceability requirements become operational. The lot code on the label is the same lot code the FDA would need in a recall. The date in the barcode is what Walmart uses to route product by expiration. The GTIN in the barcode is what ties the carton to your item setup in Walmart's system.
When all of that aligns — barcode, ASN, item file, FDA requirements — cartons move through Walmart's distribution network without anyone touching them. When any of it is off, they stop. Manual intervention costs time, delays inventory, and creates a record in SQEP.
The suppliers who get this right aren't doing anything exotic. They're running a consistent process: correct data generated from a reliable source, printed to a verified standard, applied in the right location, confirmed before the truck leaves. That's the entire job.
Walmart requires GS1-128 for all food and beverage items — not just products on the FDA's Food Traceability List. For FTL products, the barcode must carry lot number and date data. For all other food and beverage items, GS1-128 with correct Application Identifiers is required to meet Walmart's receiving and ASN standards.
An FNC1 separator is a non-printable control character inserted after a variable-length field — like a lot number — in a GS1-128 barcode. It tells the scanner where that field ends. Without it, the lot number merges with the next data field into an unreadable string. The barcode scans, but the data is unusable. It's one of the most common GS1-128 errors and the hardest to catch visually.
An ASN is an electronic record Walmart requires before every shipment arrives at a distribution center. It must contain the same lot numbers, dates, and product identifiers that appear on the carton barcodes. Walmart's system validates each barcode scan against the ASN in real time. If they don't match exactly, the carton is flagged — regardless of whether the barcode scanned correctly.
Walmart requires ANSI Grade B or better for print-and-apply labels, and ANSI Grade C or better for barcodes printed directly on corrugated board. A barcode that passes visual inspection can still fail ANSI grade requirements under automated DC scanning. An ISO/ANSI-compliant verifier is the only reliable way to confirm a label meets the standard before shipment.
Walmart tracks barcode and labeling performance through its Supplier Quality Excellence Program (SQEP). Receiving failures — scan errors, missing data, ASN mismatches — are recorded and tied to supplier performance scores. Defects accumulate over time and may result in suppliers offsetting the costs incurred from non-compliance.
Order Barcodes, Inc. helps food suppliers meet Walmart and GS1 barcode requirements. As a GS1 Channel Partner, we've supported barcode implementation across food supply chains since 1990.
As a GS1 US Channel Partner, OB maintains a team of AutoID professionals trained and certified by GS1 US. Through this blog, our team will share their expertise and highlight real-world applications of GS1 standards — covering UPC vs QR Codes, GS1 Digital Link, Sunrise 2027, FSMA 204, and RFID technology.
Reach out to us any time with questions or to place a new order!
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