GS1 Application Identifiers Explained: (01), (10), (17), and (21)
Learn how GTIN, lot, expiry, and serial fields fit together in a GS1 DataMatrix, with a worked example and field-entry checks.
A GS1 Application Identifier tells a receiving system what the following field means and how to read it. It is a data prefix, not a product number on its own. Four frequently used fields are GTIN (01), lot (10), expiration date (17), and serial number (21).
Read the fields individually
- (01) — GTIN: exactly 14 numeric digits in this element string, including the check digit. Preserve any leading zeros.
- (10) — Batch or lot: a variable-length field of up to 20 permitted characters.
- (17) — Expiration date: six numeric digits in YYMMDD order.
- (21) — Serial number: a variable-length field of up to 20 permitted characters.
The permitted character set is defined by GS1; a field accepting arbitrary keyboard text does not guarantee standards-valid data. For date preparation in UDImaker, enter a complete calendar date supported by the editor.
Break down a worked example
Use this demonstration HRI:
(01)09506000134352(17)271231(10)DEMOLOT7(21)DEMO0001
The GTIN occupies its entire 14-digit field. The next six date digits are 27 for the year, 12 for the month, and 31 for the day. The final two values identify a demonstration lot and a demonstration unit.
The AI digits are not part of their field values. In the editor's GTIN input, enter 09506000134352, not 0109506000134352 and not a value with display parentheses. In the expiry input, enter 271231, not a hyphenated date or an eight-digit year-month-day value.
Why field boundaries matter
The predefined-length GTIN and expiry fields can be located from their lengths. A variable-length lot followed by another element needs an appropriate separator so that the receiving parser can find its end. The last element does not need a trailing separator.
Do not try to replace the separator by adding spaces, commas, or visible parentheses. The FNC1 and ASCII 29 guide follows the same example through a scanner result.
Prepare and check the label
- Confirm the assigned GTIN and production values against your source record.
- Enter each value in its corresponding GS1 DataMatrix field.
- Compare the generated readable text with the source, including leading zeros and letter case.
- Decode the exported code and inspect the returned values.
- Print a sample at actual size and test the receiving workflow.
These four AIs do not describe every possible GS1 label. Add only the fields required for your product and receiving process. UDImaker provides an artwork workflow and selected input checks; it does not allocate GTINs or provide a full validation report for every GS1 AI.
Sources and technical review
Relevant primary references are listed below. These guides explain the design workflow; confirm current sector requirements and local regulations before production use.