Overview

Error 18022 appears when Amazon detects that a shipping confirmation or fulfillment feed you submit has already been processed. The duplicate entry is rejected, which can stall order status updates and create extra work for sellers handling large volumes or using automated feeds. Understanding why the error surfaces and how to prevent it keeps your fulfillment pipeline moving without unnecessary delays.

Key Points

• Duplicate detection — Amazon flags the submission when the same order‑item‑shipment combination was previously accepted, returning error 18022.
• Additive feed model — Each fulfillment file is treated as an addition to existing data; it does not overwrite earlier confirmations.
• Typical trigger — Sellers often edit a failed file, fix the errors, and resend the entire file without stripping out the rows that had already succeeded.
• No double confirmations — Amazon’s system rejects any attempt to confirm shipment of the same SKU and quantity more than once.
• Impact on reporting — Duplicate rejections clutter the processing report, making it harder to isolate genuine issues.
• Resolution requirement — Only the records that failed in the original upload may be resubmitted; all successful rows must be omitted.

How Error 18022 Occurs

1. Initial feed upload — A seller submits a bulk shipping confirmation file containing 5,000 lines. Amazon processes 4,800 lines successfully and returns error codes for 200 problematic rows.
2. Error review — The seller downloads the processing report, identifies the 200 failed lines, but leaves the 4,800 successful lines in the original spreadsheet.
3. Resubmission without pruning — The corrected file, now containing 5,200 lines (the original 5,000 plus 200 corrected rows), is uploaded again. Amazon processes the 4,800 previously accepted rows a second time, detects them as duplicates, and returns error 18022 for each duplicate entry.

What Changes in the Fulfillment Workflow