Fortnox error: 2000166

Description

This error occurs when an article number (SKU or Product ID) is sent to Fortnox but contains characters that are not allowed. For the article number to be accepted, it must comply with Fortnox rules for valid characters.

Cause

• The article number contains spaces or invalid special characters (e.g., !, ?, #, .).

• The article number is incorrectly formatted and violates Fortnox validation rules.

Resolution

• Ensure that the article number only contains:

  • Letters (A–Z, a–z)

  • Numbers (0–9)

  • The following special characters: _ - / +

• Remove or replace invalid characters in the article number.

• Then try submitting the product again.

Example

• Valid: Article number = "ABC-123"

• Valid: Article number = "shoe_45+red"

• Invalid: Article number = "ABC 123" (contains spaces)

• Invalid: Article number = "123.blue!" (contains invalid characters: . and !)