What KIX is
KIX is PostNL's (the Dutch postal service, formerly TPG Post) own 4-state postal barcode used for automated mail sorting in the Netherlands. bwip-js draws its bars directly using its own 4-state bar-pattern table -- confirmed directly: bwipp_kix calls bwipp_renlinear() itself, with no delegation to another symbology's encoder and no check-digit computation of any kind.
Generate it now
Enter a value using digits and capital letters to see a live preview.
Valid input
The value must be 1 to 500 characters, using only KIX's own 36-character alphabet: digits 0-9 and capital letters A-Z (confirmed directly against bwipp_kix.globals.kix_barchars) -- any other character is rejected ("KIX must contain only capital letters and digits"). Unlike bc412/hibcmicropdf417, KIX has no check digit -- there is no way to "get the check digit wrong," because none is computed or verified.
Key options
Supported options include includetext and height. Real, literal defaults: includetext false (no address text drawn), height -1 (auto-resolves to 0.175in/~4.4mm, a short 4-state-bar height matching the same convention already documented for Royal Mail's own 4-state postal barcode).
Output and printing
Export SVG for vector-precise mail-piece artwork or PNG for a quick proof.
Common uses
KIX appears on Dutch mail pieces (its name derives from "Klant Index," Dutch for "customer index") to encode a delivery address code for PostNL's automated sorting equipment.
Example
See the live preview above, seeded with a bwip-js-verified valid value.
Size guidance
The overall symbol's bar count -- and therefore its printed width -- scales directly with the number of characters entered, since KIX has no fixed-capacity structure the way AusPost's FCC-based capacity does.
Troubleshooting
A rejected value usually means a character outside KIX's own 36-character alphabet (digits and uppercase letters only -- lowercase letters, punctuation, and spaces are all rejected).
Related formats
Related formats already in this catalog: AusPost 4-State Customer Code (Batch 7, Australia's own 4-state postal barcode) and Royal Mail 4-State Customer Code (permanent-cohort-adjacent, the UK's own) -- each is a separately standardized national postal-automation format, not a variant of this one.
FAQ
Does KIX have a check digit?
No -- confirmed directly in bwipp_kix's own source, no checksum computation of any kind exists anywhere in its function body. Every character you enter is encoded exactly as given.
Can I use lowercase letters?
No -- KIX's own 36-character alphabet is digits 0-9 and uppercase A-Z only; lowercase letters are rejected.