Secure NFC is an Android security setting that can limit NFC card emulation when the screen is off or the device is locked, depending on the phone model and Android version. Card emulation is the feature that allows a device to behave like a contactless card in supported flows, so restricting it reduces the window in which an attacker-controlled app can interact with payment readers or access-card systems.
This matters because NFC abuse often depends on the handset being trusted in the wrong state. If malware, remote-control software, or a rogue app can trigger emulation only when the phone is unlocked, defenders gain an important control point. In practice, Secure NFC is one of several defenses that can help block contactless fraud, especially when combined with a locked screen, strong app permissions, and user awareness about suspicious app installs.