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UPC-A SYMBOLOGY

See Also:   UPC-A     EAN-13     EAN-8     Bookland     UPC 2-Digit Supplement     UPC 5-Digit Supplement     Symbology Index

Quick Links:   Background     Converting UPC-A to UPC-E     Encoding     Parity Table     Structure     Example     Converting UPC-E to UPC-A

UPC-E BACKGROUND INFORMATION

 UPC-E is a variation of UPC-A which allows for a more compact barcode by eliminating "extra" zeros. Since the resulting UPC-E barcode is about half the size as an UPC-A barcode, UPC-E is generally used on products with very small packaging where a full UPC-A barcode couldn't reasonably fit.


UPC-E uses a rather convoluted, but quite effective, method of compressing out unnecessary zeros. Keep in mind that in UPC-A there are five characters for the manufacturer code and five characters for the product code. The trick is to reduce all 10 characters into just 6 characters. How?

CONVERTING A UPC-A CODE TO UPC-E

  1. If the manufacturer code ends in 000, 100, or 200, the UPC-E code consists of the first two characters of the manufacturer code, the last three characters of the product code, followed by the third character of the manufacturer code. The product code must be 00000 to 00999.
  2. If the manufacturer code ends in 00 but does not qualify for #1 above, the UPC-E code consists of the first three characters of the manufacturer code, the last two characters of the product code, followed by the digit "3". The product code must be 00000 to 00099.
  3. If the manufacturer code ends in 0 but does not quality for #1 or #2 above, the UPC-E code consists of the first four characters of the manufacturer code, the last character of the product code, followed by the digit "4". The product code must be 00000 to 00009.
  4. If the manufacturer code does not end in zero, the UPC-E code consists of the entire manufacturer code and the last digit of the product code. Note that the last digit of the product code must be in the range of 5 through 9. The product code must be 00005 to 00009.
This may be easier to visualize in the following table:

    ORIGINAL UPC-A
    FORMAT    		 EQUIVALENT UPC-E
    FORMAT    		 UPC-A EXAMPLE UPC-E EQUIV.
    AB000-00HIJ ABHIJ0 12000-00789 127890
    AB100-00HIJ ABHIJ1 12100-00789 127891
    AB200-00HIJ ABHIJ2 12200-00789 127892
    AB300-000IJ AB3IJ3 12300-00089 123893
    AB400-000IJ AB4IJ3 12400-00089 124893
    AB500-000IJ AB5IJ3 12500-00089 125893
    AB600-000IJ AB6IJ3 12600-00089 126893
    AB700-000IJ AB7IJ3 12700-00089 127893
    AB800-000IJ AB8IJ3 12800-00089 128893
    AB900-000IJ AB9IJ3 12900-00089 129893
    ABCD0-0000J ABCDJ4 12910-00009 129194
    ABCDE-00005 ABCDE5 12911-00005 129115
    ABCDE-00006 ABCDE6 12911-00006 129116
    ABCDE-00007 ABCDE7 12911-00007 129117
    ABCDE-00008 ABCDE8 12911-00008 129118
    ABCDE-00009 ABCDE9 12911-00009 129119
You may use the following UPC-A Converter to convert a UPC-A barcode value to UPC-E. Simply enter the 12 characters of the UPC-A barcode in the first field, click the "Convert" button, and the resulting UPC-E symbol will be displayed in the field below. If the answer "Invalid" is displayed in the second field, it means the UPC-A code you provided can't be converted to UPC-E. The converter requires that you have JavaScript enabled.

    Enter UPC-A value (12 characters):
    Equivalent UPC-E:

ENCODING

 UPC-E uses the "left-hand odd" and "left-hand even" encoding character sets from the EAN-13 encoding standard.

UPC-E doesn't have a check digit encoded explicity, rather the check digit is encoded in the parity of the other six characters. The check digit that is encoded is the check digit from the original UPC-A barcode.

Additionally, UPC-E may only be used if the number system is 0 or 1. The characters encoded are encoded with odd and even parity from the left-hand columns of the EAN-13 character formats in the table previously provided. The parity used for each character depends on the number system (0 or 1) and the check digit from the original UPC-A barcode.

UPC-E PARITY ENCODING TABLE

STRUCTURE

 An UPC-E barcode has the following physical structure:

  • Left-hand guard bars, or start sentinel, encoded as 101.
  • Six data characters, encoded from the parity table above.
  • Right-hand guard bars, encoded as 010101 (a center-guard bar pattern with a trailing bar).
    NOTE: The structure of a UPC-E barcode is identical to the left-half of a standard UPC-A barcode. The only difference is that the center-guard pattern is terminated immediately by a trailing bar and trailing quiet zone.

ENCODING EXAMPLE

 For this example we will convert the UPC-A symbol "042100005264" to a UPC-E code. First, we break the UPC-A symbol into its components: Number system 0, manufacturer code 42100, product code 00526, check digit 4.

First, we make note of the fact that the number system is zero (0). We will thus use the first column of the parity encoding table. We also observe that the original UPC-A check digit was 4. Thus, consulting the table above, we see that our UPC-E barcode will be encoded with the parity "EOEEOO".

Next, we must determine how we're going to code this. We see that the manufacturer code ends in "100", so we can use the first encoding method: The first two characters of the manufacturer code, the last three characters of the product code, followed by the third character of the manufacturer code. That would be "425261". Those are the digits that we need to code using the parity pattern "EOEEOO".

  1. LEFT GUARD BARS (always the same): 101.
  2. 1st UPC-E DIGIT [4]. Encoding with left-hand even parity, 0011101.
  3. 2nd UPC-E DIGIT [2]. Encoded with left-hand odd parity, 0010011.
  4. 3rd UPC-E DIGIT [5]. Encoded with left-hand even parity, 0111001.
  5. 4th UPC-E DIGIT [2]. Encoded with left-hand even parity, 0011011.
  6. 5th UPC-E DIGIT [6]. Encoded with left-hand odd parity, 0101111.
  7. 6th UPC-E DIGIT [1]. Encoded with left-hand odd parity, 0011001.
  8. CENTAR GUARD BARS (always the same): 01010.
  9. RIGHT GUARD BAR (always the same): 1.
Remember, a "1" represents a bar and a "0" represents a space. Thus if we convert this string of numbers to their graphical representation we end up with the following barcode:


To the left of the barcode, the number "0" represents the number system code. The number "4" to the right of the barcode indicates the original UPC-A checksum digit. These two digits are printed as human-readable numbers, but are actually encoded in the parity of the other 6 numbers.

In order to see more clearly the construction of the barcode, the following graphic shows the exact same barcode but each character, or section, of the barcode is indicated by alternating colors. Above the barcode, in each colored section, is a number from 1 to 15, which corresponds to each of the "steps," or sections, described above. You may easily compare the 1-0 sequence of each step to the graphical representation below:


CONVERTING A UPC-A CODE TO UPC-E

 If you have a 6-digt UPC-E code you may use the following logic to convert it back to UPC-A. The decision on which logic to use depends on the last digit of the UPC-E Code.
  1. UPC-E code ends in 0, 1, or 2: The UPC-A code is determined by taking the first two digits of the UPC-E code, taking the last digit of the UPC-E code, adding four 0 digits, and then adding characters 3 through 5 from the UPC-E code.
  2. UPC-E code ends in 3: The UPC-A code is determined by taking the first three digits of the UPC-E code, adding five 0 digits, then adding characters 4 and 5 from the UPC-E code.
  3. UPC-E code ends in 4: The UPC-A code is determined by taking the first four digits of the UPC-E code, adding five 0 digits, then adding the fifth character from the UPC-E code.
  4. UPC-E code ends in 5, 6, 7, 8, or 9: The UPC-A code is determined by taking the first give digits of the UPC-E code, adding four 0 digits, then adding the last character from the UPC-E code.
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