Substantive Testing vs. Compliance Testing in IS Audits

Understanding the difference between substantive testing and compliance testing is essential for IS auditors and CISA candidates. These two testing approaches serve different purposes and are applied at different stages of the audit process. Knowing when to use each type of test is a frequently examined topic on the CISA exam.

What Is Compliance Testing?

Compliance testing (also called tests of controls) evaluates whether internal controls are operating effectively and consistently over a period of time. The objective is to determine whether controls are being followed as designed and whether they provide reasonable assurance of achieving control objectives.

Examples of compliance testing in IS auditing include:

Reviewing a sample of change management records to verify that all changes followed the approval process
Testing user access reviews to confirm they are performed quarterly as required by policy
Verifying that backup jobs completed successfully over a three-month period
Examining incident response logs to confirm that incidents were handled according to documented procedures

What Is Substantive Testing?

Substantive testing evaluates the integrity and accuracy of data and transactions. Rather than testing whether controls are followed, substantive tests verify the correctness of the output produced by IT systems and processes.

Examples of substantive testing in IS auditing include:

Recalculating financial totals to verify system-generated reports
Comparing data across multiple systems to identify discrepancies
Testing the accuracy of automated calculations in an application
Analyzing database records for completeness and validity

Key Differences

Objective: Compliance testing assesses control effectiveness; substantive testing assesses data integrity
Focus: Compliance testing looks at processes and procedures; substantive testing looks at outputs and results
Timing: Compliance testing examines controls over a period; substantive testing may focus on a point in time
When used: Compliance testing determines if controls can be relied upon; substantive testing provides direct evidence of accuracy

The Relationship Between the Two

Compliance and substantive testing are complementary. The results of compliance testing influence the extent of substantive testing required:

If compliance testing reveals that controls are operating effectively, the auditor may reduce the scope of substantive testing
If compliance testing identifies control weaknesses, the auditor must increase substantive testing to compensate for the reduced assurance from controls
In environments with weak or nonexistent controls, the auditor may skip compliance testing entirely and rely solely on substantive testing

Determining the Testing Approach

IS auditors select their testing approach based on several factors:

The audit objectives and scope
The maturity of the control environment
The level of risk associated with the area under review
Resource constraints and time limitations

CISA Exam Tips

The CISA exam frequently tests the distinction between these testing types. Key points to remember:

Compliance testing must precede reliance on controls for reducing substantive testing
Substantive testing provides the most direct evidence of data accuracy
When controls are weak, substantive testing becomes more important
The auditor's overall approach should be risk-based, allocating more testing effort to higher-risk areas

Practice identifying whether a described test is compliance or substantive in nature, as this distinction appears in many exam scenarios.