Sample Size Decisions

When performing tests of details of account balances, sample sizes should be determined using our firm proprietary sampling software to ensure that we can draw conclusions on the total population.

When performing tests of controls, sample sizes should be determined based on the population size in accordance with our firm guidance. Specifically,

Population Size	Sample Size
4 (Quarterly Control)	2
12 (Monthly Control)	2-4
24 (Semi-monthly Control)	3-8
52 (Weekly)	5-9
100 or less	33
101-200	35
201-500	37
500-1000	37
<1000	38

If a sample is to be used for both tests of details and tests of controls (i.e., a dual-purpose test), then it is important to ensure that the sample is sufficient to conclude on both. If the sample size for the test of details determined by the proprietary sampling software is smaller than the required sample size for the test of control (identified in the above table), then additional items must be selected and tested to ensure the effectiveness of the control.