Auditing and Assurance Standards and Guidance

Auditing Standards (Ireland)

FRC ISAs (UK and Ireland) applicable for periods beginning on or after 15 December 2010 but before 17 June 2016

ISA (UK and Ireland) 530 Audit sampling

Application and Other Explanatory Material

Sample Design, Size and Selection of Items for Testing

Sample Size (Ref: Para. 7 )

A10.	The level of sampling risk that the auditor is willing to accept affects the sample size required. The lower the risk the auditor is willing to accept, the greater the sample size will need to be.

A11.

The sample size can be determined by the application of a statistically-based formula or through the exercise of professional judgment. Appendices 2 and 3 indicate the influences that various factors typically have on the determination of sample size. When circumstances are similar, the effect on sample size of factors such as those identified in Appendices 2 and 3 will be similar regardless of whether a statistical or non-statistical approach is chosen.