Application Identifiers
The prefix codes that tell a scanner what kind of data follows in a GS1 barcode
What are Application Identifiers?
An Application Identifier (AI) is a 2-to-4 digit prefix in a GS1 barcode that defines the meaning and format of the data that follows. When a scanner reads (01)09520123456788, the (01) prefix tells it "the next 14 digits are a GTIN" – without the AI, the digits would be meaningless.
AIs are the grammar of the GS1 system. They appear in GS1-128 barcodes, GS1 DataMatrix symbols, GS1 DataBar Expanded , and GS1 Digital Link URLs (where the AI becomes a path segment like /01/). Multiple AIs can be chained in a single barcode – a shipping label might carry AI (00) for the SSCC, AI (01) for the product GTIN, AI (10) for the batch, and AI (17) for the expiry date, all in one scan.
How AIs work
Some AIs have fixed-length data (AI 01 is always 14 digits). Others are variable-length (AI 10 can be up to 20 characters). Variable-length AIs require an FNC1 separator character when followed by another AI in the same barcode, so the scanner knows where one field ends and the next begins.
Weight and measure AIs (310n–369n, 392n–393n) use the last digit to indicate the decimal point position. AI (3103) means "net weight in kg with 3 decimal places" = grams. AI (3100) means whole kilograms. This avoids transmitting a decimal point character.
Many AIs map directly to EPC RFID schemes. AI (01) + AI (21) = SGTIN . AI (00) = SSCC-96 . AI (414) = SGLN . The same identifier flows through barcodes and RFID tags.
GS1 Digital Link encodes AIs as URL path segments: https://id.gs1.org/01/GTIN/21/SERIAL. The /01/ and /21/ are the same AIs used in GS1-128 barcodes, but in a web-native format.
Industries and key AIs
AI (01) GTIN + AI (21) serial + AI (17) expiry + AI (10) batch – the "four-field" combination mandated by the EU Falsified Medicines Directive and US DSCSA. Every prescription drug pack worldwide carries these four AIs, typically in a GS1 DataMatrix.
AI (01) GTIN + AI (3103) weight in grams + AI (15) best-before + AI (10) batch. GS1 DataBar at retail checkout can carry all of these in a single compact barcode, replacing the old price-embedded PLU labels.
AI (00) SSCC is the workhorse – every pallet and carton gets a unique 18-digit shipping container code. AI (410)–AI (415) add machine-readable ship-to and bill-to addresses. Amazon, Walmart, and Target all require SSCC labels on inbound shipments.
AI (8018) GSRN on patient wristbands for positive patient identification. AI (8004) GIAI on medical equipment for asset tracking. AI (7003) expiration with hour precision for blood products – because "expires today" is not precise enough when a transfusion is at stake.
AI (8010) + AI (8011) Component/Part Identifier with serial number. Used for tracking individual aircraft components through manufacture, service life, and overhaul. Traceability of every bolt and bracket is not optional when lives depend on it.
AI (8110) North American coupon code – up to 70 characters encoding offer value, purchase requirements, and retailer ID. AI (255) Global Coupon Number maps to the SGCN-96 EPC scheme for RFID-enabled promotions.
Interesting AIs
- AI (8001) – Roll products: One of the most specialised AIs in the standard. Its 14 digits encode the width (mm), length (m), core diameter, winding direction, and number of splices in a roll of paper, film, or textile. Only useful if you manufacture rolls, but if you do, it is indispensable.
- AI (8002) – Mobile phone ESN: A relic from the 1990s when mobile handsets were tracked through the supply chain using GS1 barcodes. Largely replaced by IMEI tracking, but it remains in the standard for backward compatibility.
- AI (7003) – Expiry with hour precision: When a blood bag expires at 14:00 on Tuesday, AI (17) (which only encodes the date) is not enough. AI (7003) adds hours and minutes, making it critical for blood banks and some fresh food applications.
- AI (8200) – Extended packaging URL: The predecessor to GS1 Digital Link. Instead of encoding the GTIN in the URL itself, AI (8200) carries a plain URL alongside the barcode data. Being superseded by Digital Link QR codes, but still found on packaging.
- AIs (91–99) – Company internal: Nine AIs reserved for whatever a company wants. No interoperability guarantee – the data only means something within the company's own systems. A pressure valve for organisations that need to encode proprietary data without waiting for GS1 to define a new AI.
Complete AI reference
Search by AI number, name, industry, or keyword. Click a category to filter.
Identification
Product, asset, container, and document identifiers – the core GS1 keys.
| AI | Name | Format | Description | Links |
|---|---|---|---|---|
(253) | GDTI | N13 + X..17 | Global Document Type Identifier. Identifies a document type (e.g. tax invoice, insurance policy) and optionally a specific document serial number. Bridges paper document tracking with digital supply chain systems. | GDTI-96GDTI-174gs1-128gs1-datamatrix |
(255) | GCN | N13 + N..12 | Global Coupon Number. Uniquely identifies a coupon offer. Can include a serial number for individual coupon tracking. | SGCN-96gs1-databar |
(8003) | GRAI | N14 + X..16 | Global Returnable Asset Identifier. Tracks reusable assets – pallets, kegs, crates, gas cylinders, tote bins, roll cages. Combines a 14-digit asset type with an optional serial number for individual tracking. | GRAI-96GRAI-170gs1-128gs1-datamatrix |
(8004) | GIAI | X..30 | Global Individual Asset Identifier. Identifies a specific fixed asset – a forklift, a medical device, a piece of IT equipment. Unlike GRAI, there is no "type" layer; every GIAI is unique to one physical asset. | GIAI-96GIAI-202gs1-128gs1-datamatrix |
(8010) | CPID | X..30 | Component / Part Identifier. Identifies a component or part type within a company's numbering system. Used in manufacturing and MRO (maintenance, repair, and overhaul) to track individual components. | CPI-96CPI-VARgs1-128gs1-datamatrix |
(8011) | CPID serial number | N..12 | Serial number for a Component / Part Identifier (AI 8010). Together, AI (8010) + AI (8011) uniquely identify one specific physical component. | CPI-96CPI-VARgs1-128gs1-datamatrix |
(8017) | GSRNP | N18 | Global Service Relation Number – Provider. Identifies the provider in a service relationship. Used by utility companies, telecoms, and healthcare providers to link a customer account to a service. | GSRNP-96gs1-128gs1-datamatrix |
(8018) | GSRN | N18 | Global Service Relation Number – Recipient. Identifies the recipient (patient, customer, subscriber) in a service relationship. In healthcare, GSRN is used on patient wristbands for positive patient identification. | GSRN-96gs1-128gs1-datamatrix |
(00) | SSCC | N18 | Serial Shipping Container Code. The globally unique 18-digit number that identifies a logistics unit – a pallet, case, or parcel. Every GS1 shipping label has one. | SSCC-96gs1-128gs1-datamatrix |
(01) | GTIN | N14 | Global Trade Item Number. The 14-digit product identifier at the heart of GS1. A GTIN-13 (EAN) or GTIN-12 (UPC) is zero-padded to 14 digits. This is the number printed under every retail barcode. | SGTIN-96SGTIN-198ITIP-96ITIP-110ean-13upc-aean-8+5 |
(02) | GTIN of contained items | N14 | Identifies the trade items contained within a logistics unit. Used on a shipping container label to indicate what product is inside, when the container itself does not carry a GTIN. | SGTIN-96SGTIN-198gs1-128gs1-datamatrix |
Dates
Production, packaging, expiration, and best-before dates. All use YYMMDD format.
| AI | Name | Format | Description | Links |
|---|---|---|---|---|
(11) | Production date | N6 (YYMMDD) | The date the product was manufactured or produced. Format is YYMMDD. When the day is unknown, DD is set to 00. | gs1-128gs1-datamatrix |
(12) | Due date (payment) | N6 (YYMMDD) | The date by which payment is due. Used in trade and financial contexts rather than product labelling. | |
(13) | Packaging date | N6 (YYMMDD) | The date the product was packaged. Important for fresh food where packaging date differs from production date – for example, meat processed on day 1 but packaged on day 2. | gs1-128gs1-datamatrix |
(15) | Best before date | N6 (YYMMDD) | The date after which quality may deteriorate, but the product is not necessarily unsafe. Think of it as "best if used by". Distinct from expiration date (AI 17). | gs1-128gs1-datamatrixgs1-databar |
(16) | Sell by date | N6 (YYMMDD) | The last date on which a retailer should sell the product. After this date it is typically removed from shelves, though it may still be safe to consume. | gs1-128gs1-datamatrix |
(17) | Expiration date | N6 (YYMMDD) | The date after which the product must not be used or consumed. Legally mandated for pharmaceuticals and many food products. This is the hard stop – unlike best-before, this means "do not use after". | gs1-128gs1-datamatrixgs1-databar |
(7003) | Expiration date and time | N10 (YYMMDDHHmm) | Like AI (17), but with hour and minute precision. Format is YYMMDDHHmm – 10 digits. Used when expiry must be tracked to the hour, such as for blood products and some fresh food. | gs1-128gs1-datamatrix |
Measures & Weights
Net weight, dimensions, volume, and area. The last digit of the AI indicates the decimal position.
| AI | Name | Format | Description | Links |
|---|---|---|---|---|
(310n) | Net weight, kilograms | N6 | Net weight of the trade item in kilograms. The "n" suffix (0-9) indicates the decimal position – AI (3100) means whole kg, AI (3103) means grams (3 decimal places). This is the most common weight AI in European and international trade. | gs1-128gs1-datamatrixgs1-databar |
(320n) | Net weight, pounds | N6 | Net weight in pounds (avoirdupois). The imperial counterpart of AI (310n). Used primarily in the US market. | gs1-128gs1-datamatrixgs1-databar |
(330n) | Gross weight, kilograms | N6 | Gross weight (product + packaging) in kilograms. Used on logistics units for transport planning and warehouse operations. | gs1-128gs1-datamatrix |
(340n) | Gross weight, pounds | N6 | Gross weight in pounds. The imperial counterpart of AI (330n). | gs1-128gs1-datamatrix |
(315n) | Net volume, litres | N6 | Net volume of the trade item in litres. Used for liquid products – beverages, chemicals, fuel. | gs1-128gs1-datamatrix |
(316n) | Net volume, cubic metres | N6 | Net volume in cubic metres. Used for bulk goods and shipping calculations. | gs1-128gs1-datamatrix |
(311n) | Length, metres | N6 | Length or first dimension in metres. | gs1-128gs1-datamatrix |
(312n) | Width, metres | N6 | Width, diameter, or second dimension in metres. | gs1-128gs1-datamatrix |
(313n) | Depth, metres | N6 | Depth, thickness, height, or third dimension in metres. | gs1-128gs1-datamatrix |
(314n) | Area, square metres | N6 | Area of the trade item in square metres. Used for sheet materials, fabric, flooring. | gs1-128gs1-datamatrix |
Locations & Routing
Ship-to, ship-from, and routing codes. Most carry a 13-digit GLN.
| AI | Name | Format | Description | Links |
|---|---|---|---|---|
(254) | GLN extension component | X..20 | Extends a GLN (AI 414) to identify a sub-location within a physical location – e.g., a specific shelf, bin, or room within a warehouse. | SGLN-96SGLN-195gs1-128gs1-datamatrix |
(410) | Ship to (deliver to) GLN | N13 | The Global Location Number of the party or location to which goods should be delivered. This is the destination address in machine-readable form. | gs1-128gs1-datamatrix |
(411) | Bill to (invoice to) GLN | N13 | The GLN of the party to be invoiced for the goods. | gs1-128gs1-datamatrix |
(412) | Purchased from GLN | N13 | The GLN of the party from whom the goods were purchased. | gs1-128gs1-datamatrix |
(413) | Ship for (deliver for) GLN | N13 | The GLN of the ultimate destination (final delivery location) when different from the ship-to address. Used in multi-leg logistics. | gs1-128gs1-datamatrix |
(414) | Identification of a physical location (GLN) | N13 | Identifies a specific physical location – a warehouse, a loading dock, a shelf, a hospital ward. When paired with an extension (AI 254), it can identify locations down to bin-level granularity. | SGLN-96SGLN-195gs1-128gs1-datamatrixqr-code |
(415) | GLN of the invoicing party | N13 | The GLN of the party issuing the invoice. Used for electronic invoicing and payment systems. | gs1-128gs1-datamatrix |
(420) | Ship-to postal code | X..20 | Postal code of the ship-to destination within a single country. Used on transport labels for routing. | gs1-128 |
(421) | Ship-to postal code (with country) | N3 + X..9 | A 3-digit ISO country code followed by the postal code. Used for international shipments where the destination country must be machine-readable. | gs1-128 |
(422) | Country of origin | N3 | The ISO 3166 country code for where the product was manufactured or produced. Increasingly important for trade compliance and consumer transparency. | gs1-128gs1-datamatrix |
Logistics & Supplementary
Batch, lot, serial, count, and other supplementary data that travels alongside the primary identifier.
| AI | Name | Format | Description | Links |
|---|---|---|---|---|
(10) | Batch / Lot number | X..20 | Identifies the production batch or lot. Critical for recalls – this is how a manufacturer can say "only batch X is affected" and have every point in the supply chain identify the specific units. | gs1-128gs1-datamatrixgs1-databar |
(20) | Product variant | N2 | A 2-digit code indicating a variant of the same GTIN – for example, a different flavour or colour that shares the same product number but needs to be distinguished in inventory. | |
(21) | Serial number | X..20 | A unique identifier for an individual item within a GTIN. Combined with AI (01), this creates unit-level traceability. Mandatory for pharmaceutical serialisation (EU FMD, US DSCSA) and RFID-tagged items. | SGTIN-96SGTIN-198gs1-128gs1-datamatrixqr-code |
(22) | Consumer product variant | X..20 | Secondary data for consumer trade items. Used less frequently than AI (20) but serves a similar purpose for consumer-facing product differentiation. | |
(30) | Count of items | N..8 | The number of individual items in a variable-count trade item grouping. Used when a logistics unit contains a varying number of the same product. | gs1-128gs1-datamatrix |
(37) | Count of units contained | N..8 | Number of units contained in a logistics unit identified by AI (02). Always paired with AI (02) to say "this pallet contains N units of product X". | gs1-128gs1-datamatrix |
Trade & Pricing
Pricing, payment, order numbers, and trade-specific data.
| AI | Name | Format | Description | Links |
|---|---|---|---|---|
(400) | Customer purchase order number | X..30 | The buyer's purchase order number. Links a physical shipment to a commercial transaction. | gs1-128gs1-datamatrix |
(401) | Consignment number | X..30 | A reference number assigned by the carrier to a consignment (a group of packages shipped together). | gs1-128gs1-datamatrix |
(402) | Shipment identification number | N17 | Identifies a specific shipment as assigned by the shipper. Used for tracking a set of logistics units that travel together. | gs1-128gs1-datamatrix |
(392n) | Price, local currency | N..15 | The applicable amount payable, in the local currency. The "n" suffix indicates the number of decimal places. Used in variable-measure trade items at point-of-sale. | gs1-128gs1-datamatrixgs1-databar |
(393n) | Price, with ISO currency code | N3 + N..15 | The applicable amount payable, with a 3-digit ISO 4217 currency code. Allows unambiguous pricing across borders. | gs1-128gs1-datamatrix |
Special Purpose
Company-internal codes, coupon identifiers, and other specialised AIs.
| AI | Name | Format | Description | Links |
|---|---|---|---|---|
(90) | Mutually agreed information | X..30 | A catch-all AI for data whose meaning is agreed between trading partners but not standardised by GS1. Often used for routing codes, internal reference numbers, or pilot projects before a formal AI is assigned. | gs1-128gs1-datamatrix |
(91) | Company internal (1) | X..90 | Company internal information. The meaning is defined by the company and is not interoperable between trading partners. GS1 reserves AIs 91-99 for this purpose. | gs1-128gs1-datamatrix |
(240) | Additional product identification | X..30 | A secondary product code assigned by the manufacturer – often a catalogue number, model number, or style code that pre-dates GS1. Provides backward compatibility with legacy systems. | gs1-128gs1-datamatrix |
(241) | Customer part number | X..30 | The buyer's part number for the product. Allows the barcode to carry both the supplier's GTIN and the customer's internal SKU. | gs1-128gs1-datamatrix |
(250) | Secondary serial number | X..30 | A second serial number when a product has more than one serial identifier – for example, an internal serial and a government-mandated serial. | gs1-128gs1-datamatrix |
(7030) | Approval number of processor (country 0) | N3 + X..27 | The official approval number of a food processing establishment, paired with a 3-digit ISO country code. Used for meat traceability in the EU to identify the slaughterhouse or processing plant. | gs1-128gs1-datamatrix |
(8001) | Roll products (width, length, core, direction, splices) | N14 | Specific to roll products like paper, film, and textiles. Encodes width, length, core diameter, direction, and number of splices in a 14-digit fixed format. One of the most specialised AIs in the standard. | gs1-128 |
(8002) | Cellular mobile telephone identifier (legacy) | X..20 | Electronic Serial Number for mobile phones. A legacy AI from the era when mobile handsets were tracked through the supply chain using GS1 barcodes. Largely superseded by IMEI tracking. | |
(8110) | Coupon code (North America) | X..70 | A complex, multi-segment coupon code used in the North American coupon clearing system. Can encode offer code, value, purchase requirements, and retailer identification in up to 70 characters. One of the longest and most complex AIs. | gs1-databar |
(8200) | Extended packaging URL | X..70 | A URL pointing to product information, such as ingredients, allergens, recycling instructions, or user manuals. A predecessor to GS1 Digital Link – instead of embedding the identifier in the URL, this AI carries a plain URL alongside the GTIN. | gs1-128gs1-datamatrix |
Source
Application Identifiers are defined in the GS1 General Specifications, Section 3. The full AI reference table is available at ref.gs1.org/ai. The mapping between AIs and EPC schemes is defined in the GS1 EPC Tag Data Standard.