Method and system for identification of shared devices for fraud modeling

A system for fraud modeling based on shared computing device usage, comprising:

• a transaction database of a processing server configured to store a plurality of transaction data entries, wherein each transaction data entry is a structured data set related to a payment transaction including at least a transaction date and/or time, an account identifier, and a device identifier associated with a computing device involved in the related payment transaction;
• a receiving device of the processing server configured to receive a transaction message for a payment transaction, wherein the transaction message is formatted based on one or more standards and includes at least a plurality of data elements including at least a first data element configured to store a specific device identifier, a second data element configured to store a primary account number, and one or more additional data elements configured to store additional transaction data;
• a querying module of the processing server configured to execute a query on the transaction database to identify one or more transaction data entries where the included device identifier corresponds to the specific device identifier stored in the first data element included in the received transaction message;
• a determination module of the processing server configured to determine a fraud risk rating based on at least a plural number of unique account identifiers included in the identified one or more transaction data entries where the included device identifier corresponds to the specific device identifier over a predetermined period of time and the primary account number stored in the second data element included in the received transaction message;
• and
• a transmitting device of the processing server configured to electronically transmit at least the received transaction message and the determined fraud risk rating to a financial institution associated with the primary account number stored in the second data element included in the received transaction message.