Overview

Error 90181 is a product listing validation error that occurs when the value entered for a material composition attribute does not match Amazon's required formatting standards. This error prevents sellers from creating or updating product listings until the material data is corrected. Understanding how to properly format material composition values is essential for sellers listing apparel, jewelry, furniture, and other products where material declarations are required.

Key Points / What Sellers Need to Know

• Error trigger — This error fires when the material composition field contains a value that Amazon's system cannot parse according to its expected structure, blocking the listing from going live.
• Attribute-specific — The error message identifies the specific attribute name causing the issue, so sellers should look at the referenced field to pinpoint where the formatting problem exists.
• Common categories affected — Products in clothing, textiles, footwear, jewelry, and home furnishings are most frequently impacted because these categories require detailed material breakdowns.
• Flat file and API submissions — The error can appear whether sellers submit product data through Seller Central's Add a Product tool, inventory file (flat file) uploads, or through the SP-API.
• Reason code included — Amazon provides a reason string alongside the error that offers additional detail about what specifically is wrong with the submitted value.

Correct Material Composition Format

Amazon expects material composition values to follow a specific pattern that includes the material name and its percentage, typically formatted as a percentage followed by the material type (for example, "80% Cotton, 20% Polyester"). Each material component should be separated by a comma or semicolon, and the total percentages should add up to 100%. Sellers should avoid using special characters, abbreviations that Amazon does not recognize, or free-text descriptions in place of the structured format. If a product is made from a single material, it should still be expressed with the percentage included, such as "100% Leather." Omitting the percentage sign, using decimal values incorrectly, or listing materials without their proportions are all common mistakes that trigger this error.