Losing the lives of the emergency responders, mis encounters, and friendly fires of the policemen and soldiers are some consequences of failure in communications interoperability. From this perspective, this study aimed to explore the communications interoperability plan during joint Philippine National Police (PNP) and Armed Forces of the Philippines (AFP) internal security operations. Since this study is purely qualitative research, the exploratory survey was designed with qualitative approaches using focus group discussion, key informant interview, and document analysis were utilized as data gathering tools. The data gathered were presented in narrative form. Findings revealed that the PNP and AFP use different types of communications equipment, no joint training and no existing standards and protocols during conduct of joint internal security operations. The communications interoperability procedures will only be established during mission planning for every operation. It further revealed that there is no synchronization of PNP and AFP radio frequencies. It is only synchronized during planning, and the AFP provides the PNP communications equipment and set to one frequency for the purpose. Communications equipment are very limited. Personally-owned cellular phones were used as their primary means of communications during operations; However, cellular signal is not available in most parts of the area of operation. Therefore, findings conclude that there is no communications interoperability between PNP and AFP during joint internal security operations. It is recommended to have coordination of the PNP and AFP during procurement of communications equipment, training and in crafting of standards and protocols to achieve communications interoperability during joint PNP and AFP joint internal operations.