Overview

Amazon sellers encounter Error 18015 when they submit order‑adjustment feeds that contain negative amounts for tax or shipping‑tax fields. The platform’s validation engine rejects such entries, preventing the refund from being processed. Correcting the feed format is essential to avoid refund delays and maintain healthy buyer‑seller metrics.

Key Points

• Root cause — The error is triggered when a tax‑adjustment or shipping‑tax‑adjustment value is entered as a negative number, which Amazon’s system does not accept for refunds.
• Feed types impacted — Both XML adjustment feeds (negative <Tax> elements) and tab‑delimited adjustment files (negative item-tax-adj or shipping-tax-adj columns) can generate the error.
• Required format — Refund amounts must be supplied as positive numbers that represent the exact amount to be returned to the customer.
• Charging customers — Negative values cannot be used to bill a buyer; any additional charge must be handled outside the adjustment feed, typically through direct buyer contact and Amazon’s recharge process.
• Validation best practice — Implementing a pre‑upload check that flags any negative tax fields eliminates the error and speeds up bulk refund processing.

How the Error Occurs

1. Create adjustment feed — A seller builds an XML or tab‑delimited file to refund a portion of an order, including tax components. Example: a seller prepares a file to refund $5.00 tax for order #112‑3456789‑0123456.
2. Enter negative tax value — The seller mistakenly places “‑5.00” in the tax or shipping‑tax column, assuming a negative sign indicates a deduction. Example: the item-tax-adj field reads “‑5.00” instead of “5.00”.
3. Amazon validates feed — During upload, Amazon’s feed processor checks each numeric field. Negative numbers in tax‑adjustment fields violate the schema, so the system returns Error 18015 and rejects the entire file.