Abstract: Provided is a computing device of a group based communication system configured to securely validate a client device associated with a group-based communication interface user. An example computing device is configured to identify a validating request transmitted from the client device. If a validating request is identified, the example computing device will transmit a temporary device code to the client device associated with the group-based communication interface user and an e-mail code to an e-mail address associated with a user profile associated with the group-based communication interface user. The example computing device also stores the codes transmitted. The example computing device then receives a confirmation exchange from the client device and determines whether the confirmation exchange satisfies client device validation parameters.