CharityIndex

What is an EIN and why it matters for donors

The Employer Identification Number is a nonprofit's fingerprint: how to use it for receipts, deductions and avoiding copycats.

Published July 7, 2026 · CharityIndex editorial team

An EIN (Employer Identification Number) is the nine-digit federal tax ID every U.S. organization carries, formatted like 12-3456789. For donors it is the only reliable identifier: names repeat, EINs don't.

Why you should care

  • Tax receipts and deduction claims should reference the charity's EIN.
  • Employer gift-matching programs and donor-advised funds ask for the EIN to route your gift.
  • Verifying the EIN protects you from sound-alike and fraudulent organizations.

You can open any organization on CharityIndex directly by its EIN — just visit /ein/12-3456789 or paste the number into search.