Overview

Amazon returns error 8603 when a seller tries to overwrite a protected attribute of an existing SKU via a feed upload. The catalog treats fields such as product identifiers and variation themes as immutable after the initial creation, so any attempt to change them triggers the error. Sellers who rely on bulk feeds must understand the correct workaround to avoid listing downtime and lost sales.

Key Points

• Protected fields are read‑only — Once a SKU is live, attributes like the ASIN, UPC/EAN, or variation theme cannot be edited directly; a feed that includes a new value for these fields will be rejected with error 8603.
• Delete‑then‑recreate is the only supported fix — The catalog requires the entire SKU to be removed before a new version with the corrected attribute can be added.
• Typical locked attributes — Product ID (UPC, EAN, ISBN), variation theme, and parent‑child relationship identifiers are among the most common fields that trigger the error.
• All other data must stay identical — When rebuilding the SKU, every attribute except the one being changed must match the original record to prevent accidental overwrites.
• Timing matters — The deletion feed must be fully processed before the recreation feed is submitted; overlapping submissions can generate additional errors or duplicate listings.

How Error 8603 Happens

1. Feed submission with a changed locked attribute — A seller uploads a product‑data feed that modifies, for example, the UPC of SKU “ABC‑123”. Amazon’s catalog checks the incoming record, spots the UPC change, and flags the operation as prohibited.
2. Catalog validation rejects the update – The system returns error 8603, citing the specific attribute (e.g., “product_id”) and the SKU that caused the violation. No changes are applied, and the original listing remains unchanged.
3. Seller receives the error report – The feed processing report lists the SKU, the locked field, and the error code, prompting the seller to adjust the workflow.