Overview

On February 2026, many Amazon sellers reported receiving error 90085 when uploading inventory feeds. The error signals that two mutually exclusive columns in the same row contain data, forcing Amazon to choose one value and ignore the other. Resolving the conflict quickly is essential to keep product listings accurate and to avoid delays in bulk updates.

Key Points

• Mutually exclusive columns — The feed is rejected when both fields of a paired column set (e.g., ItemPackageQuantity and PackageQuantity) contain values for the same SKU.
• First column wins — Amazon automatically retains the value from the column that appears earlier in the template and discards the later entry, which can produce unintended attribute changes.
• Partial processing — Only the rows with the conflict are affected; the rest of the file continues to load, but the conflicted rows may display wrong data.
• Typical culprits — Legacy fields such as ItemCondition vs ConditionType, or code‑based columns like ColorCode paired with free‑text ColorName, often trigger the error when both are filled.
• Error message details — The response includes the exact header names and internal IDs (e.g., [ItemPackageQuantity] vs [PackageQuantity]), allowing sellers to pinpoint the problem rows.
• No health penalty — While the error does not affect account health metrics, it can corrupt catalog information if left unchecked.

How Error 90085 Is Detected

1. File upload and initial validation — When a seller submits a flat file through Seller Central or the SP‑API, Amazon runs a schema check that maps each column header to an internal field ID. Example: a row for ASIN B07XYZ contains values in both ColorCode (“BLU”) and ColorName (“Blue”).
2. Mutual‑exclusivity rule enforcement — The system references a rule table that marks certain field pairs as exclusive. If both fields contain non‑blank data, the rule is triggered.