UPC barcode (UPC-A)
A UPC-A barcode carries a 12-digit product number: the brand owner’s company prefix, then the company’s own number for the item, then a check digit.
Easily confused with
How to read it
The digits printed under the bars are the number the bars carry, which GS1 calls a GTIN-12. The Library of Congress describes how it divides: a company prefix of six to nine digits, assigned by the Uniform Code Council (now GS1 US); an item reference of two to five digits, which the company gives each product; and a single check digit. The check digit is worked out from the other eleven by the method in GS1’s General Specifications, and helps catch a wrongly composed number, as when one is keyed in by hand. GS1 notes that the prefix makes the number unique worldwide but does not identify the origin of the item. A till can read a UPC-A as a 13-digit EAN-13 number by putting a zero in front.
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These pages say what each code and its parts mean under the standard that defines it. A barcode identifies an item; it doesn’t say where the item was made or whether it is genuine, and the label and the maker are the place to look for that.
What the first digit means
Keyence’s barcode guide calls the first digit the number system character, which says what kind of number follows. On its table a 2 marks in-store labels for goods sold by weight and a 5 marks coupons. GS1’s current tables treat the first digit as the start of the company prefix and set a few values aside: 2 for Restricted Circulation Numbers within a geographic region, 4 for numbers used within a company, 3 for company prefixes that line up with the FDA’s labeler codes for drugs, and 0, 1 and 6 to 9 for ordinary company prefixes. GS1 lists 5 as reserved for future use, where Keyence still lists coupons.
The first UPC scanned
At just after 8 a.m. on 26 June 1974, the first item marked with the Universal Product Code was scanned at the checkout of Marsh Supermarket in Troy, Ohio, Smithsonian magazine records. The story goes that it was a multi-pack of Wrigley’s Juicy Fruit gum. The bars were George Laurer’s rectangular design at IBM, which the grocery trade’s committee chose on 30 March 1973. The magazine later corrected its account: the Smithsonian did not collect the gum.
Look-alikes
An EAN-13 carries 13 digits, and its first digit has no bars of its own. A UPC-E is the short form, with six digits under the bars.
Read next
- Next in Barcodes and QR codesEAN-13 barcodeAn EAN-13 barcode carries a 13-digit product number, the GTIN-13: a GS1 company prefix, the company’s number for the item, and a check digit. It is the shop barcode on most products outside the US and Canada, where the 12-digit UPC is used.
- The same shape in Smoke and CO alarm soundsLow-frequency 520 Hz alarm (sleeping rooms)A fire alarm in a sleeping room that sounds a low buzz in place of a high-pitched beep. It is the three-beep fire alarm rhythm at 520 Hz, which NFPA 72 requires of alarms provided to wake people in sleeping areas.
More barcodes and QR codes
The same shape elsewhere
Browse symbols drawn with letters and numbers or lines.
Sources
- GS1 General Specifications Standard, Release 26.0, ratified January 2026, GS1 AISBL, §1.2.3.4 Table 1-6; §2.1.3.1; §5.2.2.3; §5.2.5; §7.9.1
- ISSN and Bar Codes, U.S. ISSN Center, Library of Congress, UPC and EAN
- EAN | Basics of Barcodes, Barcode Information & Tips, KEYENCE Corporation, UPC; Number System Character and Data Composition of UPC-A
- The History of the Bar Code, Smithsonian magazine, adapted from Gavin Weightman, Eureka: How Invention Happens (Yale University Press), Smithsonian Institution, Troy, Ohio, 1974; the Symbol Selection Committee; editor’s note
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research
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