Internal control types

Internal control types can be either preventative or detective:

• Preventive controls: Are measures that aim to deter or prevent undesirable events such as errors or fraud from occurring. Examples of preventative controls include segregation of duties, documentation, and approval practices.
• Detective controls: Are steps to identify and correct an error or irregularity that has occurred. Examples of detective controls include reconciliations and reports.

Preventative controls are preferred, but detective controls are critical to provide evidence that the preventive controls are functioning as intended, or where it is impractical to prevent errors from occurring.