Key Takeaways

  • Internal audit provides independent, objective assurance and consulting services to add value and improve operations.
  • The Institute of Internal Auditors (IIA) sets standards and provides the definition and framework for internal auditing.
  • Internal auditors must be independent from the activities they audit and maintain objectivity in their work.
  • The audit process includes planning, fieldwork, reporting, and follow-up phases.
  • Internal audit reports should include findings, root causes, recommendations, and management responses.
Last updated: January 2026

Internal Audit Function

Quick Answer: Internal audit is an independent, objective assurance and consulting activity designed to add value and improve operations. It helps organizations achieve their objectives by evaluating and improving risk management, control, and governance processes. Internal auditors report to the audit committee to maintain independence.

Definition of Internal Auditing

According to the Institute of Internal Auditors (IIA):

"Internal auditing is an independent, objective assurance and consulting activity designed to add value and improve an organization's operations. It helps an organization accomplish its objectives by bringing a systematic, disciplined approach to evaluate and improve the effectiveness of risk management, control, and governance processes."

Internal vs. External Audit

AspectInternal AuditExternal Audit
EmploymentEmployees of the organizationIndependent CPA firm
Primary FocusOperational effectiveness, controlsFinancial statement accuracy
Reports ToAudit committee/managementShareholders/public
StandardsIIA StandardsGAAS/PCAOB Standards
ScopeBroad—operations, compliance, controlsPrimarily financial statements
FrequencyOngoing throughout yearTypically annual
RequirementVoluntary (except for some industries)Required for public companies

Role of Internal Audit

Primary Responsibilities

  1. Assurance Services — Objective assessment of evidence to provide opinions on governance, risk, and controls
  2. Consulting Services — Advisory activities to improve processes without assuming management responsibility
  3. Fraud Investigations — Investigation of suspected fraud and irregularities
  4. Compliance Review — Ensuring adherence to laws, regulations, and policies
  5. Operational Audits — Evaluating efficiency and effectiveness of operations

What Internal Audit Evaluates

AreaFocusExamples
Risk ManagementAre risks properly identified and managed?ERM framework effectiveness
Internal ControlsAre controls designed and operating effectively?Segregation of duties, authorizations
GovernanceAre governance processes effective?Board oversight, ethical culture
OperationsAre operations efficient and effective?Process improvement opportunities
ComplianceIs the organization complying with requirements?Regulatory adherence, policy compliance

Independence and Objectivity

Independence

Organizational Independence — Internal audit should report functionally to the audit committee and administratively to senior management (typically the CEO or CFO).

Reporting RelationshipPurpose
Functional Reporting to Audit CommitteeEnsures independence from management
Administrative Reporting to CEOFacilitates day-to-day operations

Objectivity

Individual Objectivity — Internal auditors must have an impartial, unbiased attitude and avoid conflicts of interest.

Threats to Independence/Objectivity

ThreatDescriptionSafeguard
Self-reviewAuditing own previous workRotation of assignments
Social pressureRelationships with auditeesProfessional skepticism training
FamiliarityLong tenure in same areaMandatory rotation policies
Economic interestFinancial ties to outcomesCompensation policies
Self-interestPersonal benefit from resultsDisclosure requirements

The Internal Audit Process

Phase 1: Audit Planning

ActivityDescriptionOutput
Risk AssessmentIdentify high-risk areasRisk-based audit plan
Annual Audit PlanPrioritize audits for the yearBoard-approved plan
Engagement PlanningPlan individual audit engagementsAudit program
Resource AllocationAssign staff and timeStaffing plan

Risk-Based Audit Planning

Internal audit uses a risk-based approach to prioritize audits:

  1. Identify the audit universe — All auditable areas
  2. Assess risk factors — Financial impact, control environment, changes, time since last audit
  3. Prioritize audits — High-risk areas first
  4. Allocate resources — Match skills to audit needs
  5. Obtain approval — Audit committee approves plan

Phase 2: Fieldwork (Audit Execution)

ActivityDescriptionPurpose
Opening MeetingMeet with managementSet expectations, gather information
WalkthroughUnderstand processesDocument understanding
TestingTest controls and transactionsGather evidence
DocumentationPrepare workpapersSupport findings
Identify IssuesDocument control deficienciesBasis for recommendations

Testing Procedures

Test TypeDescriptionExample
InquiryAsk questions of personnelInterview process owners
ObservationWatch processes occurObserve physical inventory count
InspectionExamine documents/recordsReview invoices for approval
ReperformanceRedo the control activityRecalculate bank reconciliation
Analytical ProceduresAnalyze relationshipsCompare ratios period-over-period

Phase 3: Reporting

Internal audit reports typically include:

SectionContent
Executive SummaryHigh-level overview of findings
Scope and ObjectivesWhat was audited and why
FindingsControl deficiencies identified
Root Cause AnalysisWhy the deficiency exists
RecommendationsSuggested corrective actions
Management ResponseManagement's action plan
Rating/OpinionOverall assessment

Finding Components

Each audit finding should address:

  1. Condition — What is the current state? (What IS)
  2. Criteria — What should the state be? (What SHOULD BE)
  3. Cause — Why does the gap exist? (Root cause)
  4. Consequence — What is the impact? (Effect/risk)
  5. Corrective Action — What should be done? (Recommendation)

Phase 4: Follow-Up

ActivityPurposeFrequency
Track RemediationEnsure issues are addressedOngoing
Verify ImplementationConfirm corrective actions takenPer agreed timeline
Report StatusUpdate audit committeeQuarterly
Escalate DelaysAddress overdue itemsAs needed

IIA Standards

The International Standards for the Professional Practice of Internal Auditing (Standards) are issued by the IIA and include:

Attribute Standards

StandardFocus
1000 - Purpose, Authority, ResponsibilityInternal audit charter
1100 - Independence and ObjectivityFree from interference
1200 - Proficiency and Due Professional CareCompetence and skill
1300 - Quality Assurance and Improvement ProgramInternal and external assessments

Performance Standards

StandardFocus
2000 - Managing the Internal Audit ActivityPlanning and oversight
2100 - Nature of WorkGovernance, risk, control
2200 - Engagement PlanningIndividual audit planning
2300 - Performing the EngagementFieldwork execution
2400 - Communicating ResultsReporting
2500 - Monitoring ProgressFollow-up
2600 - Communicating the Acceptance of RisksResidual risk reporting

Internal Audit Charter

The Internal Audit Charter is a formal document that:

  • Defines the purpose, authority, and responsibility of internal audit
  • Establishes internal audit's position within the organization
  • Authorizes access to records, personnel, and physical properties
  • Defines the scope of internal audit activities
  • Must be approved by the board/audit committee
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The Internal Audit Cycle
Test Your Knowledge

To maintain organizational independence, internal audit should report functionally to:

A
B
C
D
Test Your Knowledge

Which audit testing procedure involves actually redoing the control activity to verify it was performed correctly?

A
B
C
D
Test Your Knowledge

The "5 C's" of audit findings include Condition, Criteria, Cause, Consequence, and:

A
B
C
D