NFC access control uses near-field communication, a short-range radio link at 13.56 MHz. A phone or card is held close to the reader, which passes the credential to a controller. It is contactless, needs no line of sight and is separate from older low-frequency proximity cards.
NFC is the technology behind tap-to-enter phones and smart cards. Range is deliberately short, which makes the deliberate tap the point of the interaction.
Cards, phones and readers
Some sites issue NFC smart cards; others put a credential in a mobile wallet or app. Either way the reader must support the format, and the controller must accept its identifier and security level.
Choosing an NFC reader
NFC is convenient and harder to clone than legacy proximity cards, but it is not automatically encrypted end to end. Ask what protects the credential, and keep a fallback for a dead phone battery.
Related:Glossary: Access control systemGlossary: Proximity readers