Overview

Feed error 99055 is a data validation error that Amazon returns when a product listing feed contains a value in the wrong format for a given attribute. This commonly occurs when text or alphanumeric characters are submitted for fields that require purely numeric input, such as price or quantity. Understanding this error helps sellers maintain clean feeds and avoid listing delays.

Key Points / What Sellers Need to Know

• Invalid data type trigger — Error 99055 fires when a value in your feed file does not match the expected data type for a specific attribute. Amazon silently ignores the invalid value rather than applying it to your listing.
• Numeric fields are the most common culprit — Attributes like price and quantity require strictly numeric values. Submitting text, currency symbols, commas, or mixed alphanumeric strings in these fields will trigger the error.
• The bad value is discarded, not applied — When Amazon encounters the mismatch, it ignores the problematic value entirely. This means your listing may retain its old data or remain incomplete rather than updating as intended.
• The error message identifies the problem — Amazon's processing report pinpoints the exact attribute and the rejected value, making it straightforward to locate and correct the issue in your file.

How the Error Occurs

Every product attribute in Amazon's catalog system is assigned a specific data type — numeric, text, date, or boolean, among others. When you upload a feed file (whether through Seller Central flat files, third-party software, or the SP-API), Amazon validates each field against its expected type before applying changes. If a value does not conform, the system flags it with error 99055 and skips that particular attribute update. The rest of your feed may still process normally, but the flagged fields will not be updated. The error message follows this pattern: "The value [your value] for the attribute [field name] was ignored as it is not a valid [expected type]."

Common Causes and Examples

The most frequent scenario involves price fields. Sellers sometimes include currency symbols (such as "$29.99" instead of "29.99"), thousand separators ("1,299" instead of "1299"), or accidental text ("TBD" in a price column). Quantity fields trigger the same error when they contain decimals, negative signs where not permitted, or placeholder text. Date fields can also cause this error if formatted incorrectly — for example, submitting "January 5, 2026" instead of Amazon's expected date format. Another common source is copying data from spreadsheets where hidden characters or formatting artifacts get embedded in cell values without the seller realizing it.