Overview

Error 90039 is a feed processing error that Amazon Seller Central returns when your uploaded file contains data values that don't properly align with the designated column headers. This mismatch causes Amazon's system to ignore the orphaned values, which can lead to incomplete or failed product listings. Understanding how to diagnose and fix this error is essential for sellers who regularly use flat file uploads to manage their catalog.

Key Points / What Sellers Need to Know

• Unnamed column data — Error 90039 fires when one or more values in your upload file land in columns that have no header name, meaning the system cannot determine what those values represent.
• Values are silently ignored — Rather than rejecting the entire file outright, Amazon drops the misaligned values and processes whatever it can, which may result in listings with missing information.
• Column-header alignment is the root cause — The error almost always traces back to a structural problem in your flat file, such as extra commas, misplaced tab characters, or deleted column headers.
• Resubmission required — After correcting the alignment issue, you must resubmit the feed for the previously ignored values to take effect.

Common Causes

The most frequent trigger for Error 90039 is an accidental extra delimiter — typically a comma in CSV files or a tab in tab-delimited files — that pushes subsequent cell values one or more columns to the right. This can happen when product titles or descriptions contain unescaped commas, or when a seller copies data from one spreadsheet to another without matching the column structure. Another common scenario is downloading Amazon's product template, editing it in a text editor or non-standard spreadsheet application, and inadvertently removing or shifting column headers. Sellers who build their own upload files from scratch rather than using Amazon's official templates are especially prone to this error because even a single misplaced delimiter throws off the entire row.

How to Fix It

Start by opening your flat file in a spreadsheet application like Microsoft Excel or Google Sheets, which makes it easier to visually verify that every data value sits beneath its correct column header. Check the specific values referenced in the error message — Amazon typically lists which values were orphaned — and trace them back to the row where the misalignment begins. Look for extra delimiters, merged cells, or shifted data. If you're working with a CSV file, ensure that any field containing commas is properly enclosed in double quotes. Once you've confirmed that every value maps to a named column, save the corrected file and resubmit your feed through Seller Central's "Add Products via Upload" section. It's good practice to upload a small test batch of five to ten products first to confirm the error is resolved before submitting your full catalog file.