The “good” reasons to choose ISAE 3402 or ISO 27001

The "good" reasons to choose ISAE 3402 or ISO 27001 Cybersecurity

Of course there are differences between ISAE 3402 and ISO 27001, but there are also many commonalities, and that is why it is difficult to choose and to navigate. In this article, I propose to analyze these standards under several prisms, in order to enlighten you.

The origins of ISAE 3402 (International Standard on Assurance Engagements)

Before you begin to compare ISAE 3402 and ISO 27001, it is important to understand where this standard comes from and its goals.

From American law Sarbanes Oxley to ISAE 3402 via SAS 70:

ISAE 3402 originates from an American law, the Sarbanes Oxley law of 2002 (SOX), which corresponds to legislation on social responsibility vis-à-vis financial reporting. To meet this element of compliance that is the Sarbanes-Oxley law, the SAS 70 standard will supplant SOX from 1992 to 2011. From June 2011, in order to give an international dimension and to meet the need for independent standards, the standard American SAS 70 will evolve towards ISAE 3402.

The first international standard for service providers, recognized and certified by independent auditors, ISAE 3402 emphasizes the existence and effectiveness of an internal control system.

The major evolution between SAS 70 and ISAE 3402 lies in the obligation of the Management of the Organization (General Management) to produce an affirmation letter attesting to the evaluation of the effectiveness of its internal controls.
The objectives of ISAE 3402

In order to meet the transparency requirements of the international market, organizations must now demonstrate that they control the risks of their outsourced activities, entrusted to service providers, whose missions impact the finances of their customers (technology of information, insurance, brokers, human resources management, etc.)

The obligation of transparency involves the implementation of processes and procedures, which strengthen internal controls. The aim of this system is also to provide customers with reliable financial reporting, with regard to the services offered, to avoid accounting errors and fraud.

Moving towards ISAE 3402 means controlling and reducing risks by continuously optimizing the internal control system.

The objective of obtaining an ISAE 3402 report is to provide auditors (most often SOX) with reasonable assurance of the efficiency of the internal controls implemented by its service providers, in order to avoid auditing them. .

Many points in common between ISAE 3402 and ISO 27001

The common advantages of ISAE 3402 and ISO 27001 are numerous in terms of the investment required.

The common point in meeting customer requirements is above all transparency and trust.

A tool for governance and risk management, training and awareness-raising, these points are management levers ensured in each of the standards.

In a position to demonstrate compliance with internationally recognized criteria, they can thus reduce the burden of customer checks and allow advantageous competitive positioning on tenders.

Developing ISO 27001 and ISAE 3402 controls simultaneously minimizes time, effort and additional costs.

This uniformity of controls deployed then gives way to an alignment of security measures with business challenges.

ISAE 3402 is an in-depth audit focused on the effectiveness of the risk management framework. If the risks are not managed effectively, are not implemented and do not work effectively, the auditor will notify this in his report.

ISO 27001, consisting of detailed guidelines, while the approach of ISAE 3402 is based on principles.

The framework of ISO 27001 requires detailed documentation with IT policies and procedures in particular. Once the organization complies with ISO 27001, it is assured of having a solid foundation of information security principles designed and implemented.

ISO 27001 certification is proof of the organization’s ability to maintain an effective information security management system at all times.

This lack of long-term assurance has prompted many organizations to turn to a service organization control certificate to demonstrate their ability to maintain an effective IT security control environment.

The framework of ISO 27001 can then be used to support other regulatory or contractual requirements, such as ISAE 3402.


An ISO 27001 certified company can easily meet the requirements of ISAE 3402 if it includes in its scope business processes related to financial reporting.

Having ISAE 3402 in place is a good springboard to help you progress towards the requirements of ISO 27001 and can be an important milestone in the overall plan of the ISO 27001 certification project.

ISO 27001 is a framework of “good practices” for the establishment of an information security management system, it is an excellent guide for the implementation of a security program in an organization.

In contrast, the best use of ISAE 3402 is to provide an organization with a means to demonstrate that these same security “best practices” are in place and functioning effectively.

ISO 27001 is the benchmark for information security, but risks are changing and organizations are constantly demanding a higher level of assurance in terms of information security.

This level of transparency is expected today in the global economy and in a constantly evolving landscape of permanent threats.

This suggests that being ISO 27001 and ISAE 3402 is critical to meeting this level of requirement and that an organization may need both.

Either way, there are still great ways to advance your IT security assessment and continuous improvement tool.

And you, what do you need?


Rate article
Add comment