How to Choose Between SOC 2 and ISO 27001

SOC 2 or ISO 27001 Audit

Data security is no longer just an IT department concern—it’s a key driver of trust, customer confidence, and sustainable business growth. Now that businesses must manage sensitive information across multiple channels, demonstrating a robust security posture is essential. Compliance frameworks, such as SOC 2 or ISO 27001 audit, are powerful ways to show customers, partners, and investors that risks are managed effectively and that their data is safe.

In this article, I want to explore the roles of these two frameworks in strengthening your company’s data security. We’ll dive into how each operates, highlight their similarities and differences, and walk through the factors you should consider when deciding which framework best serves your business’s needs, if not both. As you read, remember that Tanner’s dedicated professionals are here to help guide you through every step of compliance and certification.

Background: Compliance Frameworks and Why They Matter

Compliance frameworks are structured guidelines that help businesses address security, privacy, and risk requirements. They’re designed to assure clients, regulators, and business partners that adequate information security controls and processes are in place and work effectively.

The nature of data protection has evolved alongside the rise of complex cyber threats and diverse regulations around the globe. The two most commonly referenced frameworks are SOC 2 (developed by the American Institute of CPAs) and ISO 27001 (published by the International Organization for Standardization). Both SOC 2 or ISO 27001 audit serve to verify that a company has taken proactive steps to protect data but with different approaches and scopes.

What Is SOC 2?

SOC 2 is an attestation standard based on the “Trust Services Criteria,” which focus on security, availability, processing integrity, confidentiality, and privacy. Organizations can select which of these criteria are most relevant to their operations. SOC 2 is particularly popular among technology service providers—like cloud hosting companies, SaaS platforms, and data centers—who process or manage customer data.

In a SOC 2 engagement, an independent auditor (a qualified CPA firm) examines the design and, in the case of a Type II report, the operating effectiveness of your internal controls. SOC 2 Type I looks at controls at a specific “point in time,” while Type II covers a historical timeline (for instance, six or 12 months).

The outcome is an attestation report that provides insights into how well the controls meet the relevant trust services criteria. This report can be immensely valuable when prospective clients want assurance about your audit processes and security posture.

One key to SOC 2 is its flexibility. The business’s IT controls and criteria can be adapted to different kinds of organizations, and the auditor’s opinion relies on the evidence provided about each area included in the scope. Though the scope can be broad, SOC 2 generally aligns well with businesses that operate primarily in the United States or serve a North American customer base.

What Is ISO 27001?

ISO 27001 is an internationally recognized standard for establishing and maintaining an Information Security Management System (ISMS). Unlike SOC 2, which is an attestation, ISO 27001 is a formal certification process. An accredited certification body reviews your ISMS to ensure it meets the standard’s requirements. This standard emphasizes a risk-based approach, requiring you to identify potential threats to your information assets and select controls to mitigate those information security risks.

The ISO 27001 process begins with a risk assessment, developing policies and procedures, and documentation of how the business will manage information security. It progresses through two main audit stages: a readiness review that checks whether the company has the correct documentation and processes, and a deeper audit of the effectiveness of each control. Once certified, a company undergoes annual surveillance checks and a recertification every three years.

The certificate you receive can be shared publicly or used in marketing materials; a practice often useful for organizations seeking global recognition. If a business plans to serve clients in multiple regions worldwide, ISO 27001 certification signals that it follows well-established security management practices.

Similarities Between SOC 2 and ISO 27001

SOC 2 and ISO 27001 focus on protecting information through effective IT controls and risk-based processes. They share similar IT controls: preventing breaches by implementing appropriate policies, security tools, and ongoing reviews. For example, both emphasize written policies, risk assessments, and continuous monitoring. Organizations that pursue either framework typically want to prove to their stakeholders that they have a comprehensive and proactive approach to data security.

Another common trait is the wealth of documentation involved. Both frameworks require evidence that a company is implementing controls and maintaining and reviewing its performance. Adopting SOC 2 or ISO 27001 helps elevate a business’s approach to information security and gives you a structured framework to identify, mitigate, and managing risks.

Differences: Certification vs. Attestation

One of the most significant differences between SOC 2 or ISO 27001 audit is how each is validated. SOC 2 results in an attestation report from a CPA firm, providing an auditor’s opinion on whether the controls meet specified criteria. ISO 27001 offers a certification, granted by an accredited body, stating that the ISMS complies with the standard. Each approach has its advantages and fulfills a different expectation.

Additionally, the geographic focus can influence a choice. SOC 2 is often a top requirement for companies in the United States; ISO 27001 holds international recognition. On the prescription side, SOC 2 is more flexible since the controls can be mapped to the trust services criteria in whichever way best fits a company’s IT environment. ISO 27001 is more prescriptive, particularly around internal audits, statements of applicability, and developing a mature management system.

Timeline considerations also come into play. A SOC 2 Type II report covers a period in the past (such as six months) and must be updated on a regular basis. ISO 27001 certification is typically valid for three years but requires annual surveillance audits. Both frameworks demand ongoing accountability, but the form of that accountability and the audit cycle structure differ.

Factors to Consider When Choosing

Several factors can guide your decision on whether to pursue SOC 2 or ISO 27001 audit, or both. One is the industry and regulatory environment in which you operate. If your customers are primarily in North America and ask for an attestation report, SOC 2 is the best choice. If, however, you have a global or multinational client base, ISO 27001 certification may be more familiar to your international partners.

Another important item to consider is resource availability. While both frameworks require considerable time and effort, ISO 27001 involves establishing and maintaining an entire management system and mandatory internal reviews. SOC 2, particularly Type I, might be an easier first step if bandwidth is limited. However, if your organization has the capacity for deeper commitments and you want to highlight a continuous improvement culture, ISO 27001 can be a strategic difference.

Budget also plays a role. Both can be cost-efficient under the right conditions, but you’ll want to account for audit fees, ongoing contract costs, and the staff needed to maintain compliance. Some organizations combine the audits when possible. If your company is going to pursue SOC 2 and ISO 27001 concurrently, the overlap in documentation can reduce the overall workload, although you’ll still need to satisfy nuances unique to each.

Finally, think about your growth trajectory. If you anticipate expansion into markets with strict security expectations, having recognized credentials upfront can remove barriers to entry. Sometimes, prospective clients might only accept recognized validations. Knowing your long-term business goals will help determine whether ISO 27001, SOC 2, or a dual approach makes the most sense.

ISO 27001 or SOC 2: Conclusion

Choosing between SOC 2 or ISO 27001 audit starts with assessing your company’s requirements and vision for the future. Adopting a structured framework can help you build trust with clients, meet regulatory expectations, and improve your security practices. While SOC 2 is often associated with U.S. markets and provides a flexible, attestation-based approach, ISO 27001 has worldwide recognition. It grants a multi-year certification that demonstrates a robust Information Security Management System.

Deciding which route to take doesn’t have to be challenging. Align your choice with your business priorities: geographic expansion, client preferences, and available resources. If blending both into your long-term strategy makes sense, the overlap in requirements means you’ll benefit from shared documentation and processes, ultimately strengthening your security posture.

At Tanner, our professionals have guided many organizations through SOC 2 and ISO 27001. Backed by experience in audit readiness, risk mitigation, and efficient control design, we tailor our approach to your specific environment so you can focus on achieving peace of mind and a secure future.