Angel Investor Due Diligence: Complete Checklist (2026)

Published 2026-04-27 · Updated 2026-05-23 · · Angel Investing · By Sahin Boydas

Step-by-step due diligence process for angel investors. What to check, who to call, and red flags to watch for.

Angel Investor Due Diligence: Complete Checklist (2026) Step-by-step due diligence process for angel investors. What to check, who to call, and red flags to watch for.

Written by Sahin Boydas — serial entrepreneur, 2x exited founder, and angel investor in 207+ startups including OpenAI, Anthropic, Scale AI, and Hugging Face. Ranked #1 most active angel investor in 2024 by Crunchbase.

This article is part of my ongoing series on angel investing, based on real experience from building a portfolio of 207+ investments across AI, fintech, robotics, developer tools, and more.

For more insights on startup investing, visit my blog or follow me on Twitter.

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