Introduction

The UPC-A barcode is the most common and well-known symbology in the
United States. You can find it on virtually every consumer goods in your
local supermarket, as well as books, magazines, and newspapers. There are a
number of UPC variants, such as UPC-E, UPC 2-digit Supplement, UPC 5-digit
supplement.
UPC-A encodes 11 digits of numeric data along with a trailing check
digit, for a total of 12 digits of barcode data.
0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Structure of a UPC number
An UPC-A number consists of four areas: (1) The number System; (2)The
manufacturer code; (3) the product code; (4)The check digit. Normally the
number system digit is printed to the left of the barcode, and the check
digit to the right. The manufacturer and product codes are printed just
below the barcode, separated by the guard bar.
| NS |
Description |
| 0 |
Regular UPC code |
| 1 |
Reserved |
| 2 |
Weight Items |
| 3 |
Drug/Health Items |
| 4 |
In-store use on non-food
items |
| 5 |
Coupons |
| 6 |
Reserved |
| 7 |
Regular UPC code |
| 8 |
Reserved |
| 9 |
Reserved |
Number System. The number system is the first digit in the UPC
number to identify the type of the product. For example, if the barcode
starts with digit 5, this barcode is a coupon code.
Manufacturer Code. The manufacturer code is assigned by UCC
council to each manufacturer or company which distributed goods that uses
UPC-A barcode. To apply for a manufacturer code, visit
http://www.uc-council.org/ . Note
that UCC has started to assign manufacturer code longer than 5 digits to
conserve the numbering resource. In Canada,
Electronic Commerce Council of Canada is responsible for assigning
5-digit manufacturer code. ECCC can be contacted via
http://www.eccc.org.
Product Code. The product code is assigned by the manufacturer.
The product code is a 5-digit number so it can accommodate 99,999 possible
product codes for each manufacturer. That is far enough for any
manufacturer in the world!
Check Digit. The check digit is used to verify that the barcode
is generated or scanned correctly. The check digit is calculated based on
the rest of the barcode digits. Read the following section to learn how to
calculate the check digit.
The nominal X dimension is 13 mils. The printable X dimension
ranges from 10.4 to 24 mils.
Coupon Code

The coupon code is a UPC code with number system 5. A coupon code
contains four areas: (1) Number system 5; (2) Manufacturer Code; (3)
Product Family code and value code; (4)check digit.
For example, the coupon at the right side indicates that its family code
is 186 and value code is 70, and the manufacturer of the goods has a UCC
code 43000.
Check Digit Calculation
UPC-A check digit is calculated using standard Mod10 method. Here
outlines the steps to calculate UPC-A check digit:
- From the right to left, start with odd position, assign the odd/even
position to each digit.
- Sum all digits in odd position and multiply the
result by 3.
- Sum all digits in even position.
- Sum the results of step 3 and step 4.
- divide the result of step 4 by 10. The check digit is the number
which adds the remainder to 10.
A web-based free utility to calculate UPC-A check digit can be found
here.
Encoding
A UPC-A symbol can be divided into two halves, each consisting of six
digits separated by a center guard bar pattern. The whole symbol is surrounded by two guard bar patterns. The same digit has different
encoding depends whether it is in the left halve or in the right
halve. The encoding pattern for digits in the left halve always starts with
a space while the one for digits in the right halve always start with
a bar and ends with a space.
A UPC-A symbol has the following structure:
- Start guard bars, always with a pattern bar+space+bar.
- Left halve, six digits encoded using the encoding schema A or
B;
- Center guard bars, with a pattern space+bar+space+bar+space.
- Right halve, six digits encoded using the encoding
schema C.
- Stop guard bars, always with a pattern bar+space+bar.
Web Tool
At barcode knowledge library we provide free web-based utilities for
readers to calculate check digits, performing number conversions. To
calculate UPC check digit, refer to this page. If you have
purchased Morovia UPC/EAN/Bookland Font, you may consider checking out
this
page for additional utilities for character mapping.
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