Internal audit: definition, types and simple process

Published Thursday 5 March 2026

Table of contents

• What is an internal audit?
• What do internal auditors do?
• Internal audit vs external audit: key differences
• Why are internal audits important for small businesses?
• Key areas of focus in internal audits
• Types of internal audits
• Key roles in an internal audit
• How to conduct an internal audit
• Tips for successful internal audits
• Streamline your audit processes with Xero
• FAQs on internal audits

Key takeaways

• Conduct internal audits at least once a year to improve efficiency, reduce risks, and ensure compliance by examining your business processes, financial records, and controls with fresh eyes.
• Focus your audit on the areas that matter most to your business by starting with a risk assessment to identify your biggest concerns, whether that's fraud prevention, operational efficiency, or regulatory compliance.
• Follow the four-stage audit process of planning, fieldwork, reporting, and follow-up to ensure your findings lead to real improvements rather than just documentation.
• Assign audit responsibilities to existing staff like bookkeepers or managers, or bring in outside consultants if your team lacks audit experience, since internal audits don't require a CPA to be effective.

What is an internal audit?

An internal audit is an independent review of your business's finances, processes, and systems to identify risks and areas for improvement, a practice governed by the official Global Internal Audit Standards. The results stay within your company and guide how you make internal decisions.

Auditors often work for the company, but small businesses may bring in outside consultants or auditors to help. Either way, the findings are used to strengthen operations, not shared with external stakeholders.

Common internal audit examples for small businesses include:

• Risk management: reviewing strategies to identify and reduce business risks
• Insurance compliance: checking that your practices meet policy requirements, such as cyber insurance rules about firewalls or network access
• Process efficiency: examining workflows to find bottlenecks and redundant steps

What do internal auditors do?

Internal auditors examine your business operations, test controls, and recommend improvements. Their goal is to help you run a safer, more efficient business.

Day-to-day activities typically include:

• Reviewing documents: examining financial records, policies, and procedures for accuracy and compliance
• Testing controls: checking whether safeguards work as intended
• Interviewing staff: talking with employees to understand how processes actually work
• Analysing data: looking for patterns, errors, or anomalies in your numbers
• Reporting findings: documenting issues and recommending specific improvements

Small businesses often assign audit tasks to existing staff. A bookkeeper, accountant, or manager often takes on audit tasks, or you can bring in an outside consultant for specific reviews.

Internal audit vs external audit: key differences

Internal audits improve your operations; external audits verify your financials for outsiders. Understanding the difference helps you know which type you need.

Internal audits:

• are conducted by employees or hired consultants
• focus on processes, controls, and efficiency
• results stay within the company
• happen as often as you choose
• aim to identify risks and drive improvement

External audits:

• are conducted by independent audit firms
• focus on financial statement accuracy
• results are shared with investors, lenders, or regulators
• are required annually for public companies
• aim to provide assurance to outside stakeholders

Most small businesses can focus on internal audits, unless lenders, investors, or industry regulations require external audits. Internal audits, however, benefit businesses of any size by helping you spot problems early and strengthen operations.

A strong internal audit function can even speed up external audits, with research showing delays can be reduced by 4.1 to 6.6 days when external auditors rely on their work.

Why are internal audits important for small businesses?

Internal audits help small businesses improve efficiency, reduce risks, and stay compliant. They give you a chance to step back and examine your processes with fresh eyes.

Here's what internal audits can do for your business:

• Improve efficiency: identify redundant processes and streamline workflows
• Reduce risks: spot vulnerabilities before they become costly problems
• Ensure compliance: verify you're meeting financial regulations and insurance policy requirements

For example, an internal audit of your fraud prevention controls would compare your documented procedures to actual workflows. The findings help you close gaps and strengthen protections.

Key areas of focus in internal audits

Internal audits examine the effectiveness of internal controls, compliance with regulations, and the accuracy of financial reports, often using established guidance like the COSO Internal Control – Integrated Framework to improve confidence in data. Common focus areas include:

• Financial records: reviewing the accuracy of your numbers, data entry processes, access controls, and who's responsible for financial reporting
• Operational processes: examining workflow steps to identify redundant tasks, inefficient processes, and opportunities to improve
• Fraud prevention: assessing risks from internal threats like employee theft and external threats like phishing or cyberattacks, plus reviewing controls designed to prevent them. Learn more about risks of internal fraud
• Risk management: evaluating your biggest business risks and how well you're prepared to reduce them or respond to a crisis

Types of internal audits

The four main types of internal audits are operational, compliance, financial, and IT audits. The focus of each audit determines its type and scope.

• Operational audits: evaluate internal processes to assess efficiency and resource use
• Compliance audits: verify the business follows laws, industry regulations, and internal policies
• Financial audits: examine the accuracy of financial reports and the effectiveness of internal controls
• IT audits: assess cybersecurity measures, data protection practices, network access controls, and team training

Key roles in an internal audit

Internal audits involve three key roles: the auditor, oversight committee, and management. In small businesses, one person may fill multiple roles.

• Internal auditor: leads the process, evaluates records or processes, and maintains objectivity to minimise bias
• Audit committee: identifies audit priorities, approves the audit plan, and reviews findings
• Management: allocates staff and resources, then implements audit recommendations

Large corporations may have a chief audit executive reporting to the board. In smaller companies, roles often overlap. A bookkeeper might audit financial reports, while a team manager audits workflows.

How to conduct an internal audit

The internal audit process follows four main stages: planning, fieldwork, reporting, and follow-up. Each stage builds on the last to help you identify issues and implement improvements.

1. Plan your internal audit

Planning sets the foundation for your audit. Start by identifying what you want to audit and why.

Begin with a risk assessment to identify your most significant business risks. Then design an audit scope to address them.

Match your audit focus to your concerns:

• Fraud concerns: audit financial statements and money handling processes
• Efficiency concerns: audit workflows and operational processes
• Compliance concerns: audit policies and regulatory requirements

2. Complete the fieldwork and execution

Fieldwork is where you gather evidence and test your controls. Your specific activities depend on the audit focus.

Common fieldwork activities include:

• reviewing documents and records
• analysing processes against documented procedures
• interviewing employees and managers about their roles
• observing workflows in action
• testing controls to assess their effectiveness

For example, an IT security audit might include sending simulated phishing emails to identify which employees need additional training.

3. Write your audit findings report

Your audit findings report documents what you discovered and recommends improvements. This report becomes the roadmap for strengthening your business.

Include your observations, identified risks, and specific action items. Share the report with leadership, whether that's an audit committee, owners, or managers who can implement changes.

4. Follow up on audit implementation

Following up ensures your audit findings lead to real change. Follow-up ensures your recommendations lead to real improvements.

Schedule a review 30 to 90 days after the audit to assess what's been implemented. Check whether changes are working as intended and adjust your approach as needed.

Tips for successful internal audits

Consider these tips to ensure your audit goes smoothly and helps you make your business safer, more efficient, and compliant with necessary regulations.

• Focus on the benefits: treat the audit as an opportunity to improve your business
• Get team buy-in: ensure everyone understands the audit's purpose, with visible support from management
• Plan in advance: define the scope, set clear goals, and assign responsibilities before you start
• Secure the right expertise: bring in outside specialists if your team lacks audit experience
• Gather the right data: invest in tools like accounting software or process mapping to access the information you need

Streamline your audit processes with Xero

Streamline your internal audits with numbers at your fingertips using Xero. Generate reports, track financials by project or department, and analyse data in real time.

Ready to make internal audits smoother? Get one month free and simplify your audit process from day one.

FAQs on internal audits

Here are answers to common questions from small business owners about internal audits.

What are the different types of internal audits?

The four main types are operational, compliance, financial, and IT audits. Operational audits evaluate efficiency, compliance audits verify you follow regulations, financial audits examine reporting accuracy, and IT audits assess cybersecurity.

What's the difference between an internal audit and an external audit?

Internal audits improve operations and stay confidential. External audits verify financial accuracy for investors, lenders, or regulators. See the comparison section above for more details.

How often should internal audits be conducted?

Conduct internal audits at least once a year, with more frequent reviews for high-risk areas. Increase frequency if you're actively working to reduce risks or improve compliance.

Do I need a CPA to conduct internal audits?

Internal audits can be conducted by anyone with relevant knowledge of your processes. While CPAs bring valuable expertise, anyone with relevant knowledge of your processes can conduct an internal audit. Small businesses often use bookkeepers, managers, or outside consultants.

What happens if you find issues during an internal audit?

Audit issues show you how to improve. Document findings in your report, share with leadership, and create an action plan to address each issue.