In this paper, an absorptive filter-integrated switch (FIS) using switchable T-shape resonators is presented. The FIS was made up of two absorptive T-shape resonators and integrated with single pole double throw (SPDT) switch. A simple mathematical analysis of isolation and insertion loss of filter-integrated SPDT switch is discussed. PIN diodes were used as the switching elements for the SPDT switch and to reconfigure between the band-stop and bandpass responses. The proposed absorptive FIS design could be used for internet of things (IoT) applications such as Zigbee and Bluetooth at an operation frequency of 2.45 GHz. As a result, the proposed FIS exhibited low magnitude of insertion loss and high isolation. Therefore, the key advantages of the proposed FIS design are low insertion loss, high isolation, and good return loss at both ON- and OFF-state ports. © 2020, Electromagnetics Academy. All rights reserved.