Overview

Amazon sellers frequently encounter error 90004201 when their product feeds contain material composition data that does not follow Amazon’s strict formatting rules. The issue appears during feed processing and blocks listings from going live until the data is corrected. Properly structuring percentages, separators, and component labels is essential for apparel, textiles, and any items that require a material breakdown, making this error a critical hurdle for sellers who rely on bulk uploads.

Key Points

• Percentage required — Every fabric entry must start with a numeric percentage, e.g., “100% cotton” or “70% wool, 30% nylon.” Omitting the number triggers the error.
• Comma as intra‑component delimiter — When a single component contains more than one fabric, separate each fabric with a comma, not a slash, plus sign, or ampersand.
• Semicolon for separate components — Use a semicolon to distinguish different layers or parts of a product, such as “Shell: 100% polyester; Lining: 100% nylon.”
• Exact 100 % total per component — The sum of percentages for each component must equal 100 %; values that fall short or exceed this total cause the feed to be rejected.
• Resubmit after fixing — Once the composition field complies with the format, the feed must be uploaded again for Amazon to reprocess the listing.

How to Fix Error 90004201

1. Audit the material composition column — Open your flat file or inventory feed and locate the column that stores fabric data. For a men’s T‑shirt, you might see “cotton” instead of “100% cotton.” Replace any bare fabric names with a percentage‑first format.
2. Apply comma separation within each component — If a product’s outer shell blends fabrics, rewrite the entry as “60% cotton, 40% polyester.” Remove any slashes (e.g., “cotton/polyester”) or plus signs (e.g., “cotton + polyester”).
3. Insert semicolons between distinct parts — For a jacket that has a shell and a lining, format the field as “Shell: 100% nylon; Lining: 100% polyester.” Ensure there is a single semicolon separating each part, with no extra punctuation.