According to the IIA guidance, reviewing and approving payroll timesheets by the timekeeper before processing is considered least effective in managing the risk of payroll fraud. While this procedure might detect some errors or irregularities, it does not provide a robust control against fraud because the timekeeper can collude with employees or fail to review timesheets adequately. On the other hand, procedures such as comparing payroll lists to personnel records, deactivating payroll database access upon termination, and validating changes to payroll by the personnel department involve checks and balances that are more effective at preventing or detecting fraudulent activities.

IIA Practice Guide: Managing the Business Risk of Fraud: A Practical Guide

IIA Standards and Guidance: IPPF – Practice Guide