Sampling risk is one of the many types of risks an auditor may face when performing the necessary procedure of audit sampling. Audit sampling exists because of the impractical and costly effects of examining all or 100% of a client's records or books. As a result, a "sample" of a client's accounts are examined. Due to the negative effects produced by sampling risk, an auditor may have to perform additional procedures which in turn can impact the overall efficiency of the
audit.