NFC with Arduino

Good morning,

I want to make a project but first I need to ask a question. Is possible to use the smartphones as tags ?

Thanks.

"Near-field communication (NFC) is a set of communication protocols that enable two electronic devices, one of which is usually a portable device such as a smartphone, to establish communication by bringing them within 4 cm (1.6 in) of each other".

Your question about using Smartphones at tags really does not make sense but smartphones can be used for NFC.