Systems (100) and methods (700) for operating a security tag of an Electronic Article Surveillance ("EAS") system. The methods involve: executing on a mobile Point Of Sale ("POS") device (104) an application operative to control operations of a peripheral device (190) attached to the mobile POS device for facilitating performance of a purchase transaction; receiving, by the mobile POS device a request to detach the security tag from an article; and communicating a message from the mobile POS device to the peripheral device via a first short range communication. The message is configured to cause the peripheral device to perform operations to facilitate a detachment of the security tag from the article. Next, a signal is communicated from the peripheral device to the security tag. The signal causes an actuation of a detachment mechanism of the security tag or a heating of an adhesive disposed on the security tag.