Expense tracking is the process of recording, categorizing, and reviewing business purchases so finance teams can see where money goes and verify that spending is legitimate. In practice, it may include card transactions, receipts, mileage, invoices, and approvals, all tied to employee, project, or department records.
It matters in cyber security because expense systems contain sensitive financial and identity data and are a common target for fraud. Attackers may try to alter receipt images, submit fake reimbursements, abuse stolen business cards, or compromise finance software to hide unauthorized purchases. Defenders use expense tracking to spot unusual merchants, duplicate claims, off-hours spending, and mismatches between receipts and transaction logs. Strong controls such as approval workflows, receipt validation, role-based access, and audit trails help reduce both cyber-enabled fraud and internal misuse.