Amazon’s Tax Exemption Review system doesn’t publish its exact “algorithm,” but in practice it behaves like a rule-based and OCR (text-recognition) filter that auto-rejects a large share of bad or incomplete certificates before a human ever looks at them.
Here’s what it typically checks and why certificates get rejected:
Form structure and type
The system looks for a valid, state-specific exemption form (e.g., that state’s official resale or nonprofit form), not a generic letter.
If the layout, fields, or required statements don’t match expected patterns, it’s flagged.
Legibility and format
Blurry scans, photos with shadows, or partial pages often fail OCR.
Non-PDF uploads or multi-page docs where the key page is missing also cause rejection.
Data matching
The legal name, address, and tax ID on the certificate must match the account details exactly.
If the state, jurisdiction, or exemption type doesn’t align with where exemption is being claimed, it’s rejected.
Dates and validity
Because much of this pre-check is automated, even small formatting or mismatch issues can trigger a denial, which is why clean, state-correct, machine-readable PDFs with perfectly matched account information are so important.
