← All disapproval codes
critical 20000

Error 20000 — Flat-file format error

What this means

Amazon couldn't parse your flat-file (Excel/TSV) — usually missing required columns, wrong column order, or wrong template version.

Why this happens

Submitting an outdated flat-file template, modifying column headers, or saving as the wrong file type.

How to fix it

  1. Download the latest flat-file template from Seller Central → Catalog → Add Products via Upload → Download an Inventory File.
  2. Don't modify the column headers — Amazon validates against exact column names.
  3. Save as the format Amazon expects (.txt for tab-delimited, not .xlsx).
  4. Resubmit with the corrected file.

Common pitfalls