Japanese postal barcode

Revision as of 17:08, 4 November 2020

The Japanese postal barcode is used in mail sorting for Japan. It encodes an 7-digit postal/zip code plus an optional alphanumeric address code. The symbology allows the coding of the digits 0-9, letters A-Z, and hyphen. An alternative mode allows for pre-encoding SHIFT-JIS (CP936) as alphanumerics.

This sort of bar code system is regarded as "four-state" because there are four types of bars, classified by presence of ascenders and/or descenders. This sort of system is transcribable using DAFT notation. These sorts of bar codes are used by a number of countries in their postal systems, though the specific symbologies by which they encode characters can vary.

The scheme

There are no full descriptions of how the barcode works in English. The relevant article on Japanese Wikipedia, Wikipedia:ja:郵便追跡サービス, has no information either. Someone with insider or reverse engineering knowledge is needed to figure this out.

The start and end bars are FD and DF. Each character takes up three bars. Padding with TDA is performed to fill 20 chars.

Utilities

• Barcode generator: Japanese postal bar code
  • TEC-IT Reference (Covers general information and CP932 transcription)

Links

• Barcode structure, seagull scientific (covers alphanumeric, but does not have exact values for each three-unit)
• Japan Post bar code info
• Discussion of the encoding of these bar codes
• Japanese postal/zip code directory