Overview

Amazon may display error code 100603 when a seller attempts to push a large cost or price adjustment through Seller Central. The code signals that Amazon’s pricing validation engine has placed the change on hold for a deeper review, typically lasting 24–48 hours. Sellers should care because the hold can delay time‑sensitive pricing moves, affecting competitiveness and inventory turnover.

Key Points

• Hold notification, not a failure — The message means the update was received but is pending review; the change has not been rejected.
• Triggered by big jumps — Adjustments that raise or lower a price by a sizable percentage (e.g., a 30 % increase or a 25 % discount) automatically flag the review system.
• Standard review window — Amazon usually completes the assessment within one to two days, after which the new price is applied.
• No immediate fix required — Sellers generally only need to wait; resubmitting the same change will not speed up the process.
• Marketplace protection — The hold helps prevent accidental under‑pricing, over‑pricing, or manipulative pricing that could harm buyers or the buy‑box algorithm.

How the Review Process Works

1. Submission detection — When a seller uploads a cost update that deviates sharply from the current listing price, Amazon’s automated pricing engine flags the entry. Example: A seller raises the price of a kitchen gadget from $19.99 to $29.99, a 45 % jump, prompting the flag.
2. Automated analysis — The system cross‑checks the proposed price against historical price trends, competitor listings, and internal pricing policies. Example: The engine notes that similar products average $24–$26, flagging the $29.99 price as an outlier.
3. Potential manual review — If the automated check cannot reconcile the change, the request is queued for a pricing specialist to verify legitimacy. Example: A manual reviewer may contact the seller’s account manager to confirm the cost increase reflects a supplier price hike.