Substantive sampling working paper
Auditing provides reasonable assurance, not full assurance. This is because auditors are not able to perform procedures on all transactions, and need to select samples of transactions for execution purposes.
ISA530 Provides us with the process and requirements for sample sizes. Although auditors may comply with these requirements, they are not always documented properly on the audit file.
This document takes into consideration all the documentation requirements of ISA530, while also providing guidance on calculating the sample size