> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://developer.americanexpress.ferndocs.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://developer.americanexpress.ferndocs.com/_mcp/server.

# Introduction

Enhanced Authorization enables Merchants to share additional transaction data with American Express, such as email address, IP address, shipping information, phone numbers, and more. American Express uses its best-in-class machine learning models to link together thousands of factors including the Customer spending patterns, Merchant profiles and real-time transaction data to significantly improve our ability to assess risk and distinguish between a legitimate Customer and a fraudster.

The Enhanced Authorization service is set up to first receive the Enhance Authorization API call, and then the Authorization message, with some time gap between the two calls (e.g., `200 milliseconds`).