Understanding Error Code MYO1004: How to Fix Missing or Incorrect Shipment Information in Seller Central
On 2026-02-13 Amazon sellers may see validation error MYO1004 when confirming shipments. The error is triggered by missing fields, a tracking number that doesn’t match carrier patterns (e.g., UPS must start with “1Z”), or a ship date outside today or recent past.
Overview
On February 13 2026 Amazon sellers may encounter validation error MYO1004 while confirming shipments in Seller Central. The error appears when essential shipment details are missing, incorrectly formatted, or conflict with carrier specifications, blocking the confirmation step. Resolving the issue quickly is crucial to keep order timelines on track and protect account health metrics.
Key Points
- Root trigger — MYO1004 activates whenever a mandatory field in the shipment confirmation screen is left blank, contains an invalid entry, or does not follow the carrier‑specific format.
- Tracking number format — The tracking number must match the pattern required by the selected carrier; a UPS number that does not start with “1Z” or a USPS number that is not 20‑22 digits will cause the error.
- Ship‑date rule — The ship date can only be today’s date or a recent past date; dates set in the future or more than a few days ago are rejected.
- Complete form requirement — Every required field—carrier, tracking number, ship date, and package weight—must be populated before the system accepts the submission.
- Bulk‑upload sensitivity – In feed‑based uploads, a single mis‑aligned column or an extra space in the tracking field can generate MYO1004 for every line in the file.
- Third‑party integration risk – Shipping software that maps carrier names incorrectly (e.g., “US Postal Service” instead of “USPS”) will produce the same validation failure.
How to Resolve MYO1004
- Select the correct carrier — Open the shipment confirmation page, click the carrier dropdown, and choose the exact carrier that shipped the package. Example: If the parcel was sent via UPS, ensure “UPS” is selected, not “FedEx”.
- Validate the tracking number format — Compare the entered tracking string with the carrier’s official pattern.
- UPS: must begin with “1Z” followed by 16 alphanumeric characters (e.g., 1Z999AA10123456784).
- USPS: 20‑22 numeric digits (e.g., 9400110200881234567890).
Analysis & Recommendations
Why This Matters
If MYO1004 isn’t fixed, orders stay in “Pending Shipment,” pushing the Late Shipment Rate above Amazon’s 4 % threshold and risking performance notices or suspension. Buyers receive no tracking updates, increasing inquiry volume and A‑to‑Z claims.
Key Takeaways
- MYO1004 appears when any required field—carrier, tracking number, ship date, weight—is blank or malformed.
- UPS tracking must begin with “1Z” plus 16 alphanumeric characters; USPS requires 20‑22 numeric digits.
- Ship dates can only be today’s date or a recent past date; future dates like 2026-02-20 cause rejection.
- A single formatting error in a bulk‑upload feed can generate MYO1004 for every line.
Recommended Actions
- →In Seller Central, go to Manage Orders > filter ‘Shipment Not Confirmed’ and correct each MYO1004 entry by selecting the exact carrier and entering...
- →Before bulk uploads, run a spreadsheet macro to validate tracking columns against carrier patterns (1Z prefix for UPS, 20‑22 digits for USPS).
- →Add a pre‑submission checklist to your SOP: verify carrier selection, tracking format, ship date (today or recent past), and that weight is entered.
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