Abstract: Systems and methods are provided to facilitate fraud detection in payments made via mobile communications. In one aspect, a system includes a data storage facility configured to store payment transaction records associated with phone numbers; and an interchange that includes a common format processor and a plurality of converters configured to interface with a plurality of controllers of mobile communications in transmitting premium messages to the phone numbers to collect funds for making payments on behalf of users of the phone numbers. The system includes a fraud detection engine configured to use the payment transaction records to detect a potentially fraudulent activity in payments requested via a phone number and configured to communicate with a server of a telecommunication carrier of the phone number to further process the activity based on an indication of abnormality in the telecommunication usage pattern of a mobile phone at the phone number.