The YubiKey 5C NFC FIPS is the USB-C and NFC key in Yubico's FIPS series. Under the casing it is the same hardware as the standard 5C NFC. The one difference is that this version carries FIPS 140-3 validation, the current US federal standard now replacing the retiring 140-2 generation. If that certification has to appear on your paperwork, this is the version to buy. If it does not, the standard key does the same job for less.
It is a multi-protocol key. FIDO2 and WebAuthn handle passkeys and phishing-resistant sign-in, and it also does FIDO U2F, PIV smart card, OATH-TOTP and HOTP, OpenPGP, YubiKey OTP, static password, and HMAC-SHA1 challenge-response. In practice one key can secure Microsoft 365 and Entra ID logins, act as a smart card, and hold your authenticator codes, with no app and no phone to depend on.
The hardware is deliberately plain, which is the point. It is keychain-sized, runs firmware 5.7, has no battery and no moving parts, and is crush- and water-resistant. USB-C plugs into current laptops and NFC taps against a phone.
Our take: choose the FIPS version when a standard, a contract or an auditor specifically asks for FIPS 140-3. That covers government and IRAP-adjacent work, defence supply chains, and regulated settings where the validation is a box that has to be ticked. For a typical Australian SMB rolling out phishing-resistant MFA across Microsoft 365, the standard 5C NFC is the sensible pick and the FIPS premium buys nothing you will use.
Rolling these out is less about the key than the plan. Buy at least two per person so nobody is locked out when one goes missing, register both against each account, and set your recovery path before you hand them over. Check that your identity provider is configured to accept FIDO2 or PIV, because the key is only as useful as the systems set to trust it.
