KIX

KIX (Klant IndeX) is the barcode PostNL uses for addresses on Dutch mail. It encodes the postcode and house number, so sorting machines can route mail without reading the printed address.

Decode one

Scan or paste a barcode and see every part of it.

Make one

Generate a valid barcode from fields.

Where you’ll see it

Business mail in the Netherlands, printed under the address.

Anatomy

KIX uses the same bars and characters as the Royal Mail 4-State code: each character is four bars, each in one of four states. The data is the address, written with no spaces:

Part	Characters	Example
Postcode	6	`1234AB`
House number	Up to 5	`56`
`X` and an addition	Up to 6 after the `X`	`XC`

So postcode 1234 AB, house number 56C is 1234AB56XC. Unlike Royal Mail’s code, KIX has no start and stop bars and no checksum.

Check digit

None. Nothing in the barcode detects a misread, so PostNL’s machines and your app have to check the result against real addresses.

Royal Mail 4-State: the code KIX is based on, with start and stop bars and a checksum.

Gotchas

The X is a separator, not a letter in the address. Split on the first X after the house number.

Scanning it in your app

ScanField("Address barcode", text: $kix)
    .barcodeTypes(.postal)
    .validate(.matches(/^\d{4}[A-Z]{2}\d{1,5}(X[A-Z0-9]{1,6})?$/))

KIX has no check digit, so a pattern is the best defense against a bad read. See Validation.

Specification

PostNL KIX-code (Dutch): information and documentation downloads.

Reference

Retail (GTIN)

Logistics and industrial

2D

Postal

Documents

Decode one

Make one

Where you’ll see it

Anatomy

Check digit

Gotchas

Scanning it in your app

Specification

Decode one

Make one

​Where you’ll see it

​Anatomy

​Check digit

​Variants and related types

​Gotchas

​Scanning it in your app

​Specification

Where you’ll see it

Anatomy

Check digit

Variants and related types

Gotchas

Scanning it in your app

Specification