Interleaved 2 of 5 barcode
The dense numeric barcode that ITF-14 is built on, used for internal carton and tote numbering.
Also known as: ITF, I 2/5, USS ITF
What is Interleaved 2 of 5?
Interleaved 2 of 5 is a numeric-only linear barcode that encodes digits in pairs, one in the bars and one in the spaces, which makes it very dense and very tolerant of poor print. Its weakness is partial reads: without a fixed length, a check digit, or bearer bars a scanner can decode a fragment as a valid shorter number. ITF-14 is the GS1 application of this symbology with all three protections built in.
Encodes: An even number of digits. Odd-length data gets a leading zero.
How Interleaved 2 of 5 is structured
Each pair of digits is encoded together: the first digit in five bars, the second in the five spaces between them, two of each wide. That interleaving is the density and also the reason a partial scan can look like a complete symbol.
| Part | Length | What it means |
|---|---|---|
| Start pattern | 4 elements | Narrow bar, narrow space, narrow bar, narrow space. |
| Digit pairs | N pairs | Odd-position digit in the bars, even-position digit in the spaces. |
| Optional check digit | 1 digit | Mod 10 with 3-1 weighting; padded to an even total with a leading zero if needed. |
| Stop pattern | 3 elements | Wide bar, narrow space, narrow bar. |
Specifications
- Character set
- Digits 0 to 9 only
- Length
- Variable but always even; fix the length in the scanner where you can
- Check digit
- Optional mod 10; mandatory in ITF-14
- Wide-to-narrow ratio
- 2.0 : 1 to 3.0 : 1
- Quiet zones
- 10X on the left and right
- Density
- Two digits per five bars and five spaces; among the densest linear numerics
- Standard
- ISO/IEC 16390
Dimensions are GS1 General Specifications targets. Confirm against the retailer’s current routing guide before a print run.
Where it is used
- Internal carton and tote numbering in older warehouse systems
- Air freight and distribution labels that predate Code 128
- Film canisters and some industrial parts
- The symbology underneath every ITF-14 case code
Internal numbering, or the raw form of a case code
Plain Interleaved 2 of 5 is printed by a WMS for its own numbering schemes. When the same symbology carries a GTIN-14 for a trading partner it becomes ITF-14, gains bearer bars and a mandatory check digit, and moves to the packaging supplier as artwork. If you find yourself putting a 14-digit case number in plain ITF, use ITF-14 instead.
Mistakes that cost money
Odd digit counts
Encoders prepend a zero to make the count even. Your 13-digit number scans as 14 digits and no longer matches the record.
Short reads
A scan path that clips the symbol can decode as a valid shorter number. Set a fixed length in the scanner, add a check digit, or add bearer bars.
Using plain ITF for a GTIN-14
Retailers expect ITF-14 with bearer bars and the GS1 check digit. Plain ITF of the same digits may scan but fails their label specification.
Ratio too tight on corrugate
Ink spread on brown board closes narrow spaces. Keep the ratio near 2.5 : 1 and the X-dimension large.
How Endless handles Interleaved 2 of 5
Endless maps legacy ITF carton and tote numbers to unit records the same way it handles Code 128, and generates proper ITF-14 case codes from the catalog’s pack hierarchy when a case is destined for a retailer.
Frequently asked questions
What is the difference between Interleaved 2 of 5 and ITF-14?
Same bars, different rules. ITF-14 is Interleaved 2 of 5 carrying exactly 14 digits (a GTIN-14) with a mandatory GS1 check digit and bearer bars, printed to GS1 dimensions. Plain ITF is any even number of digits with none of those protections.
Why does my scanner sometimes read the wrong number from an ITF label?
Partial reads. The scan beam crossed part of the symbol and decoded a fragment as a shorter valid number. Fix it with a fixed-length setting, a check digit, bearer bars, or all three.
Related symbologies
Definitions in the glossary
- Case Pack→
The fixed number of units a product is packaged and sold in per case.
- Warehouse Management System (WMS)→
The system that runs day-to-day warehouse operations — receiving, slotting, picking, shipping.
Browse the full barcode symbology guide.
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