GS1-128

Type1D Linear

MentionedIT

Completeness86%high

GS1-128

Overview

GS1-128 (formerly UCC/EAN-128) is an application profile of the code-128 barcode symbology, defined and governed by the GS1 General Specifications [1]. It is not a separate symbology: it uses the same bar/space encoding as Code 128 (standardised as ISO/IEC 15417:2007 [2]), but reserves the FNC1 function character — placed immediately after the start character — as a flag that the symbol carries GS1 Application Identifier (AI) data [3]. This single structural rule turns a generic Code 128 symbol into a self-describing, machine-parseable data carrier for the supply chain.

GS1-128 is the global standard for supply-chain shipping and packaging identification — pallet and case labels, the Serial Shipping Container Code (SSCC), pharmaceutical-distribution outer packaging, and healthcare logistics all rely on it [1]. Its defining feature is that one symbol can concatenate several AI element strings — for example a GTIN, a use-by date, and a batch number — into a single, scannable string of structured data.

History

1989 — UCC/EAN-128 publication [3]: The Uniform Code Council (UCC) (the US numbering authority) and the European Article Numbering association (EAN International) jointly published a profile of Code 128 for structured supply-chain data. The profile defined how to embed GS1 Application Identifiers — GTINs, batch numbers, dates, weights, and other logistics fields — inside a Code 128 symbol, using the FNC1 character to mark and delimit them. The result was named UCC/EAN-128.

2005 — Rebrand to GS1-128 [3]: When UCC and EAN International merged into GS1 (Global Standards One), UCC/EAN-128 was renamed GS1-128. The technical specification was unchanged — only the name and governing body changed. The standard is now maintained as part of the GS1 General Specifications [1].

Underlying symbology lineage [2, 4]: The base symbology, Code 128, was developed by Computer Identics Corporation in 1981 and standardised internationally as ISO/IEC 15417:2007. GS1-128 inherits that bar/space encoding, the three character subsets (A, B, C), and the modulo-103 check character; it adds only the GS1 data-formatting conventions on top.

Technical specification

GS1-128 is a structured-data profile of Code 128 [1, 3, 4]:

Parameter	Value
Base symbology	Code 128 (ISO/IEC 15417:2007)
Symbology family	1D linear
Distinguishing feature	FNC1 immediately after the start character
Data model	GS1 Application Identifiers (AIs) + element strings
Character subsets	A, B, C (inherited from Code 128)
Field separator	FNC1 (used after variable-length AI fields)
Check character	Modulo-103 (inherited from Code 128)
Variable length	Yes — no fixed code length
Practical max data	Up to 48 encoded characters per symbol (GS1 limit) [5]
Quiet zone	10 × module width on each side (minimum)
Bidirectional reading	Yes

The FNC1 rule [1, 3]: A Code 128 symbol becomes a GS1-128 symbol when the FNC1 function character is placed in the first position after the start code. Scanners that decode this leading FNC1 transmit it as the symbology identifier ]C1, signalling to the receiving application that the data is GS1-formatted and should be parsed by Application Identifier rather than treated as free text.

Application Identifiers (AIs) [1, 6]: An AI is a numeric prefix (2–4 digits) that defines the meaning and format of the data field that follows. Common AIs include:

AI	Meaning	Format
(00)	SSCC — Serial Shipping Container Code	18 digits, fixed
(01)	GTIN (trade item number, GTIN-14 form)	14 digits, fixed
(10)	Batch / lot number	up to 20 alphanumeric, variable
(11)	Production date	6 digits YYMMDD, fixed
(17)	Expiration / use-by date	6 digits YYMMDD, fixed
(21)	Serial number	up to 20 alphanumeric, variable
(310n)	Net weight (kg)	6 digits + decimal indicator
(37)	Count of trade items	variable

Concatenation and the separator role of FNC1 [1, 3, 6]: A single GS1-128 symbol can carry multiple AI element strings back-to-back. Fields with a predefined fixed length (such as (01) GTIN-14 or (17) date) need no separator — the scanner knows where they end. Fields of variable length (such as (10) batch or (21) serial) must be terminated by an FNC1 character when another AI follows, so the parser can find the boundary. This is why FNC1 plays a dual role in GS1-128: a flag in the first position, and a field delimiter thereafter.

Worked example — the payload (01)03453120000011(17)191125(10)ABCD1234 encodes a GTIN-14 ((01), fixed 14 digits), a use-by date of 25 November 2019 ((17), fixed YYMMDD), and batch ABCD1234 ((10), variable). Because (10) is the last field, no trailing FNC1 separator is required; if another AI followed (10), an FNC1 would be inserted after the batch value. The parentheses are a human-readable convention only — they are printed in the text line beneath the bars but are not encoded in the barcode itself.

Use cases

GS1-128 is the dominant 1D carrier for structured supply-chain, logistics, and healthcare data [1, 3]:

Logistics unit labels (SSCC) — every commercial pallet or shipping unit moved through modern distribution carries a GS1 logistics label whose primary barcode is a GS1-128 encoding the SSCC (00). This is the canonical GS1-128 deployment.
Case and carton labelling — outer cases use GS1-128 to combine GTIN (01), batch (10), and expiry (17) so a single scan captures product, lot, and date for traceability.
Pharmaceutical distribution — bulk drug-distribution outer packaging uses GS1-128 (with GTIN, batch, expiry, and serial AIs) alongside data-matrix/GS1 DataMatrix on the consumer-facing inner packs.
Healthcare and UDI — medical-device and healthcare logistics use GS1-128 to carry the Unique Device Identifier (UDI) element strings on larger packaging where linear space is available.
Variable-measure retail and food — (310n) net-weight and date AIs let GS1-128 label variable-weight goods (meat, produce) for distribution.
Fresh-food and cold-chain traceability — batch/lot (10) plus production (11) and expiry (17) dates enable recall management and shelf-life control.

Why GS1-128 is chosen for these contexts [1, 3]:

It encodes the standardised AI data structure that downstream warehouse, ERP, and EDI systems already understand.
It rides on Code 128, so every existing supply-chain scanner reads it with no new hardware.
Multiple data fields fit in one symbol, and multiple symbols fit on one logistics label.
It is royalty-free, inheriting Code 128's public-domain status.

Implementations

Because GS1-128 is Code 128 plus formatting rules, any Code 128 encoder/decoder can produce or read the bars; GS1-128 support specifically means the library understands AI formatting and FNC1 placement [7]:

JavaScript — metafloor/bwip-js — ~2 400★, active 2026. Barcode Writer in Pure JavaScript; supports GS1-128 (and GS1-128 Composite) with AI parsing in browser and Node.js.
C / C++ — Zint (zint/zint, libzint) — comprehensive open-source generator written in C with explicit GS1-128 (and HIBC) support and AI checking.
Java + many ports — zxing/zxing — 34 000★, active 2025. Decodes Code 128 / GS1-128 (returns the ]C1 symbology identifier and FNC1 markers) alongside QR, PDF417, Data Matrix.
Python — python-barcode, treepoem (wraps Barcode Writer in Pure PostScript, which has full GS1-128 AI support).
PHP — picqer/php-barcode-generator.
Thermal printers — Zebra (ZPL), Honeywell, SATO, and TSC label printers generate GS1-128 directly from their command languages, including FNC1 insertion.
Industrial scanners — every commercial 1D scanner (Cognex, Datalogic, Honeywell, Zebra, SICK) decodes GS1-128 and most can be configured to parse and re-transmit the AI fields.

Open standards documentation:

GS1 General Specifications — define the GS1-128 profile, the FNC1 rule, and the Application Identifier registry.
ISO/IEC 15417:2007 — the canonical specification of the underlying Code 128 symbology.

Comparison

vs. code-128 (the base symbology) — Code 128 is the general-purpose symbology that can encode any of the 128 ASCII characters. GS1-128 is a constrained application of it: same bars, same check digit, but a mandatory leading FNC1 and a strict GS1 AI data model. Choose plain Code 128 for arbitrary alphanumeric strings (tracking numbers, internal IDs); choose GS1-128 when the data must be standardised AI element strings that GS1-aware systems will parse.

vs. data-matrix (GS1 DataMatrix) — GS1 DataMatrix encodes the same GS1 Application Identifier structure, but in a 2D matrix. The 2D version is far smaller and fits on a single consumer drug-carton face, but needs a 2D-capable imager. GS1-128 dominates pallets and outer packaging where horizontal label space is plentiful and 1D laser scanners are entrenched; GS1 DataMatrix dominates retail consumer packaging and pharmaceutical inner packs where space is scarce.

vs. gs1-databar — GS1 DataBar (formerly RSS) is a compact 1D family that also carries GS1 AIs and is targeted at small retail items (loose produce, coupons) scanned at point of sale. GS1-128 is the logistics-and-distribution carrier — larger, higher capacity, multiple AIs per symbol — while GS1 DataBar is the small-footprint POS carrier. Both encode the same AI data model.

vs. itf (ITF-14) — ITF-14 (Interleaved 2 of 5) is the GS1 outer-carton variant restricted to a single 14-digit GTIN. GS1-128 is far more flexible — it can add batch, dates, weights, and serials in the same symbol — but consumes more printable width and is more sensitive to print quality than the robust ITF-14.

Fun facts

The parentheses in (01), (17), (10) are never encoded in the barcode [1, 6] — they appear only in the human-readable text line to delimit Application Identifiers for the eye. The scanner reconstructs field boundaries entirely from the AI registry (fixed-length AIs) and FNC1 separators (after variable-length AIs). A common integration bug is software that tries to transmit or strip the literal parentheses.

FNC1 does double duty in GS1-128 [3]: the same function character means "this is GS1 data" when it appears in the first position, and "this variable-length field ends here" when it appears between two AI element strings. No other Code 128 profile loads a single control character with two distinct semantic roles.

The name changed but not a single bar did: when UCC/EAN-128 became GS1-128 in 2005, the rebrand was purely organisational — the merger of UCC and EAN into GS1 — and existing symbols, scanners, and labels remained fully valid and unchanged [3].

Status

Active, foundational, and ubiquitous in the supply chain [1, 3]:

GS1 General Specifications maintain GS1-128 as a current, core barcode standard.
The underlying ISO/IEC 15417:2007 Code 128 spec has been stable for nearly two decades.
Universal scanner support — inherited from Code 128 — across every industrial 1D scanner.
Public domain / royalty-free, like Code 128.

Strategic context:

GS1 maintains GS1-128 in parallel with GS1 DataMatrix and GS1 DataBar; all three carry the same AI data model, and the choice is driven by available label space and existing scanner infrastructure rather than by data capability.
GS1-128's grip on the logistics unit label (SSCC), case labelling, and distribution-level healthcare packaging remains unchallenged, even as 2D codes encroach on consumer-facing and small-footprint applications.
No deprecation is planned.

Sources

Deployments

Found in the following country reports (grep across reports/countries/):

IT — IT-italy.md — GS1-128 / Code 128 used in supply-chain and retail distribution.

Regions / aggregations not mapped to a single country

Universal

Deployments

Found in the following country reports (grep across reports/countries/):

IT — IT-italy.md

Regions / aggregations not mapped to a single country

Universal