Overview

Amazon rejects inventory uploads that contain repeated column headings, triggering Feed Error 6000 during the validation stage. The issue appears when a flat file or template lists the same header more than once, causing the entire submission to fail. Resolving the duplicate‑header problem quickly restores the flow of new listings and inventory updates.

Key Points

• Duplicate headers block the feed — Amazon’s upload engine requires every column name to be unique; a file that lists “price” twice will be rejected with Error 6000.
• Manual edits are the usual culprit — Sellers who copy‑paste rows, rearrange columns, or type headings by hand often introduce a second “sku” or “quantity” column without noticing it.
• Out‑of‑date templates add hidden duplicates — Downloading a template from an older version of Seller Central and merging it with a current file can create overlapping headings such as “item‑weight” that look different but are read as identical by the system.
• Trailing spaces masquerade as duplicates — A header entered as “product‑name ” (with a trailing space) appears distinct in Excel but is treated the same as “product‑name” during Amazon’s scan, leading to a false duplicate detection.
• Hidden columns can escape visual checks — Columns hidden in the spreadsheet UI still exist in the file; if a hidden column shares a name with a visible one, the validation will flag it even though the seller cannot see it at first glance.
• The remedy is removal or consolidation — Deleting the extra column or merging its data into the remaining column eliminates the error, allowing the corrected file to be uploaded without further issues.

How Error 6000 Is Detected

1. Header scan — As soon as the file is uploaded, Amazon reads the first row and builds a list of all column titles. For example, a file containing “price” in column C and again in column J will generate a duplicate entry in the scan list.
2. Duplicate comparison — The system compares each title against the others; any match, even if case‑insensitive or padded with spaces, is flagged. In a spreadsheet where “sku” appears in both column A and column M, the comparison step marks both as duplicates.