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The Universal Product Code (UPC)
has been successfully employed in the retail industry
in the United States and Canada since 1973. UPC is a
coding system as well as a symbology; it is designed
to uniquely identify a product and its manufacturer.
There are three versions in UPC code; Version A, Version
E and Version D. (Version D was originally defined but
never used.)
The actual UPC code is a 12-digit code. The first
6 digits represent the manufacturer of the labeled item.
The UPC-A Code and the assignment of manufacturer ID
numbers is controlled in the United States by the Uniform
Code Council located in Dayton, Ohio. The next 5 digits
identify a particular product assigned by the manufacturer.
The twelfth digit is a check character, based on previous
11 digits of data. The first digit of the 6-digit field
is also the number system character. UPC is a fixed
length, numeric, continuous symbology using four element
widths.
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The first digit of the UPC-A Code represents the number
system as well as being part of manufacturer's identification.
Number systems "0", "6" and "7" are assigned with the
five digits to identify the manufacturer; others have
special uses as follows:
The first digit of the UPC A code says what the code
contains:
- 0: Manufacturer identification
numbers
- 1: Reserved
- 2: Random weight items marked
at the store (articles where the price varies by the
weight: for example meat. The code is produced in
the store and attached to the article.)
- 3: National Drug Code (NDC) and
National Health Related Items Code (HRI).
- 4: In-store marking without format
(UPC Code which can be used without format limits)
- 5: UPC Coupon
- 6: Manufacturer identification
numbers
- 7: Manufacturer identification
numbers
- 8: Reserved
- 9: Reserved
The final digit is a check digit whose value is mathematically
based on the first eleven digits encoded in the symbol.
A weighting scheme (the weighting alternates between
1 and 3) is used in its calculation, so the check digit
also protects against transportation errors if the data
is manually entered.
The check digit of the UPC code
You never have to enter the check digit if you use
ActiveBarcode - it is calculated and added automatically.
But you can add it, if you want. To understand how the
check digit is found here is an example for UPC A. It
is also works for UPC E, which just has fewer digits:
UPC-number: 012300 70321
check digit: unknown at this time
Digits: 0 1 2 3 0 0 7 0 3 2 1
Multiply with: 3 1 3 1 3 1 3 1 3 1 3
Results: 0 1 6 3 0 0 21 0 9 2 3 Total = 45
Divide by 10: 45/10 = 4 remainder 5
To find check digit: 10 - remainder = check digit
check digit: 5
UPC-E
UPC-E is a variation of the UPC-A symbol.
The UPC E Code is also a numeric code which is able
to display digits from 0-9. UPC E has 8 digits where
the first digit is always "0" and is also
added by ActiveBarcode automatically - you do not need
to enter the leading zero.
It has six explicitly encoded data digits, and an implicitly
encoded seventh digit (check character). It is suited
for identifying products in small packages.
In addition to the requirement that the first digit
of the barcode (number system) must be zero, there are
four rules that determine what UPC codes can be printed
using the compressed UPC-E format:
- If the last 3 digits of the manufacturer's
number are 000, 100, or 200, the valid product code
numbers are 00000 - 00999 (1,000 numbers).
- If the last 3 digits of the manufacturer's
number are 300, 400, 500, 600, 700, 800, or 900, the
valid product code numbers are 00000 - 00099 (100
numbers).
- If the last 2 digits in the manufacturer's
number are 10, 20, 30, 40, 50, 60, 70, 80, or 90,
the valid product code numbers are 00000 - 00009 (10
numbers).
- If the manufacturer's number
does not end in zero, the valid product code numbers
are 00005 - 00009 (5 numbers).
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