The Codabar is separated into the variant with 18 different Element Widths, sometimes also called Monarch Code, and the variant with only two element widths, also called Codabar Matrix or ABC-Codabar.
Codabar was developed by the Monarch Marking System Division of Pitney Bowes.
The variant with the 18 different element widths cannot be printed on every printing system, as the preset values cannot be related to any commonly used printer solution. Therefore, this version is employed less and less.
Because of the above-mentioned reasons, the Codabar with two element widths came into existence, printable on almost every printing system.
In 1977, the ABC-Codabar was determined for the use in blood banks by the "American Blood Commission" (ABC).

Symbol Examples

Example of a Codabar symbol with the start character "A", the stop character "A", six functional digits (123456) and one check character ($):


Codabar symbol with the start character A, the stop character A

Symbol Designations

The code Codabar with only two element widths is sometimes also called

  • USD-4 or
  • 2 of 7 Code or
  • USS-Codabar
  • Codabar Matrix or
  • ABC-Codabar.

The code Codabar with 18 different element widths is sometimes also called

  • Monarch Code or
  • Standard Codabar or
  • Codabar Classic.

Areas of Application & Branches of Trade

  • Medical area
  • Health sector
  • Photography business


Advantages / Potencies

Disadvantages / Shortcomings

  • Low information density

Codeable Character Set

  • 10 digits 0 1 2 3 4 5 6 7 8 9
  • 6 special characters: - $ : / . +
  • 4 start/stop-characters: A B C D

Symbol Properties

  • Code type: discrete (the space – intercharacter gap – between the single characters contains no information).
  • Elements per Symbol Character: 7, 2 or 3 wide elements and the rest narrow elements, displayed in form of 4 bars and 3 Spaces.
  • Self-Checking characters: yes (the characters are intrinsically safe, meaning that a change within the character is detected to be an error).
  • Symbol width: variable (the amount of data characters within the symbol can, depending on existing agreements, be variable or variable up to a defined maximum).
  • Ratio (ratio between the wide and the narrow elements): the ratio should range between 2.0 : 1 and 3.0 : 1.
  • Bi-directionally readable: yes (the barcode symbol can be read in two directions, i.e. forwards or backwards).
  • Check character: an optional check character (by using a check character – symbol check digit – substitution errors can nearly all be detected).
  • Character density: 10 or 11 to 12 or 14 modules per symbol character, including the space – intercharacter gap – occurring between the fonts, and according to the ratio between the wide and the narrow elements.
  • Necessary characters containing no functional characters: 20 to 26 modules, according to the ratio between the Wide and the Narrow Element.

Check Digits & Data Security

The Codabar is a Self-Checking barcode, applying a check algorithm on each character within the code. Self-checking barcodes are intrinsically safe, i.e. a change within a character is detected to be an error and is thus not being read at all.
Substitution errors can, therefore, only occur when two or more individual printing errors occur within one character.

By using an additional Check Character, which is automatically generated by the "Visual Bar Code Designer" if necessary, this substitution error can also be easily detected.

Symbol Description

A symbol – starting from the left – consists of

  • a leading Quiet Zone,
  • a Start-Character
  • One or more Symbol Characters (functional characters)
  • Possibly an optional Check Character (symbol check character), automatically generated by the "Visual Bar Code Designer" if necessary.
  • A Stop Character
  • A closing quiet zone
  • Human Readable Text
    A human readable translation of the data characters encoded in the symbol
    (and possibly the check digits) should usually be printed along with the symbol.
    The size of the characters and the font type are not specified. As long as the quiet zones are not touched, the human readable text can be printed at any given spot near the symbol. Usually, the human readable text is situated below the symbol.

A Space between the barcode characters, the intercharacter gap, separates the single barcode characters within the Symbol.