Overview

Error 18628 is a feed processing error that Amazon sellers may encounter when submitting data through feed files in Seller Central. The error indicates that a value provided in your feed doesn't meet Amazon's expected format, data type, or validation requirements. Understanding how to diagnose and resolve this error can save sellers significant time and prevent delays in listing updates, inventory changes, and other critical operations.

Key Points / What Sellers Need to Know

• Invalid input format — This error fires when a value you've submitted doesn't match what Amazon expects for that particular field, whether that's a specific data type, character set, or structure.
• Common triggers include special characters — Unsupported symbols, unexpected formatting, or invalid characters embedded in your feed data are frequent causes of this validation failure.
• Field length limits apply — Amazon enforces maximum character or size limits on many feed fields, and exceeding these thresholds will trigger error 18628.
• The fix requires reviewing your feed data — You'll need to identify the specific value causing the problem, correct it to match Amazon's accepted parameters, and resubmit your feed.

What Causes Error 18628

Error 18628 occurs when Amazon's feed processing system encounters input data that fails validation checks. There are three primary scenarios that trigger this error. First, the value entered in a feed field doesn't conform to the expected data type — for example, submitting text where Amazon requires a number, or using an incorrectly formatted date. Second, the field contains characters or symbols that Amazon's system doesn't support, such as certain special characters or non-standard formatting. Third, the input exceeds the maximum allowed length or size for that particular field, which varies depending on the data element in question.

How to Diagnose the Problem

The most effective way to pinpoint the cause of error 18628 is to download and review your feed processing summary report. This report identifies the specific value and field that triggered the validation error, giving you a clear starting point for troubleshooting. Once you've located the problematic entry, compare it against Amazon's accepted parameters for that field. Check whether the data type is correct — strings, numbers, and dates each have specific formatting requirements. Also verify that the value falls within any documented length or size constraints for the field.