Two terms appear frequently in conversations about technology assessment in M&A: technology due diligence and technical audit. They are often used as if they mean the same thing. They do not — and confusing the two is one of the most common mistakes buyers make when evaluating a technology acquisition.

The difference is not semantic. It has direct implications for what risks get surfaced, what decisions get informed, and what the acquirer is left exposed to when the deal closes.

What a Technical Audit Is

A technical audit is an assessment of a specific technical system or component against a defined set of standards or criteria. It answers a narrow question: does this system meet the standard it is being measured against?

Technical audits are commonly used in several contexts: a security audit that measures a platform’s posture against ISO 27001 or SOC 2 requirements; a code audit that assesses quality against defined coding standards; a compliance audit that checks whether a system meets regulatory requirements such as GDPR or HIPAA; or an accessibility audit that evaluates a web application against WCAG guidelines.

A technical audit is a valuable tool. Within its defined scope, it provides a reliable, repeatable assessment against objective criteria. The limitation is precisely that scope: it answers the question it was designed to answer, and nothing more.

What Technology Due Diligence Is

Technology due diligence is a fundamentally different exercise. It is not an assessment against a predefined standard — it is an investigation designed to surface everything a buyer needs to know about a technology platform to make an informed acquisition decision.

Where a technical audit asks “does this system meet standard X?”, technology due diligence asks “what is the true state of this technology, and what are the implications for this deal?”

A rigorous TDD examines the platform across every dimension that could affect deal value: architecture and scalability, code quality and technical debt, security posture, infrastructure resilience, engineering team capability and stability, IP ownership, vendor dependency, integration complexity, and post-close value creation potential. It is not constrained to a predefined checklist — it follows the evidence, prioritises the findings by commercial impact, and delivers a picture of the technology that an investment committee can act on.

What Buyers Get Wrong

Mistake 1: Substituting a security audit for security due diligence

This is the most common and most consequential confusion. A security audit — even a thorough one against a recognised framework — tells you whether the platform meets the criteria of that framework. It does not tell you whether the security architecture is fit for the acquirer’s purposes, whether there are vulnerabilities outside the audit’s scope, or whether the security posture will hold under the specific threat profile the platform will face post-acquisition.

Security due diligence requires a broader assessment: examining security architecture across the application, infrastructure, and organisational layers; evaluating the security implications of the technical debt identified elsewhere in the TDD; and understanding how security risk interacts with the acquirer’s specific integration plans and regulatory environment.

Mistake 2: Commissioning a code audit and calling it TDD

A code audit tells you about the codebase. It tells you nothing about the infrastructure the code runs on, the team maintaining it, the architectural decisions constraining it, the vendor dependencies creating lock-in, or the IP ownership questions affecting what the acquirer actually owns.

Code quality is one dimension of technology due diligence. Treating a code audit as a substitute for TDD is like commissioning a structural survey of one room in a building and concluding you understand the whole property.

Mistake 3: Using a compliance audit as a proxy for technical assessment

A GDPR compliance audit, a SOC 2 review, or an ISO 27001 gap assessment tells you about the target’s compliance posture. It does not tell you about the architecture, the technical debt, the scalability, or the engineering team. These are entirely different questions. Compliance and technical quality frequently diverge — a platform can be fully compliant and deeply problematic from a technical standpoint, or technically excellent and compliance-immature.

Mistake 4: Applying the wrong standard for the context

Technical audits are designed for operational contexts — ongoing monitoring, periodic compliance validation, internal quality assurance. They are not designed for M&A. The question an acquirer needs answered is not “does this system meet a standard?” — it is “what am I buying, what is it worth, and what will it cost me to make it what I need it to be?” That question requires a methodology built for the M&A context, not repurposed from an operational one.

The AI and Security Dimension

Two areas where the audit vs. TDD distinction is particularly consequential in 2026:

Security: The proliferation of cyber threats means that a point-in-time security audit — conducted six months before an acquisition closes — may not reflect the current security posture of the target. Technology due diligence conducted as part of the deal process provides a current assessment, integrated with the broader technical picture, and directly actionable for deal structuring. A historical audit certificate is not a substitute.

AI systems: Technical audits have not yet caught up with AI. There are no universally accepted audit frameworks for evaluating AI model quality, training data compliance, or AI talent concentration risk. In the absence of established audit standards, technology due diligence — which is investigation-led rather than standard-led — is the only methodology capable of surfacing the most important risks in an AI acquisition.

Choosing the Right Assessment

Technical audits and technology due diligence are not in competition — they serve different purposes. A recent, high-quality security audit or SOC 2 report from the target is useful input to a TDD. A code quality report produced by the target’s own engineering team can inform the assessment. But none of these are substitutes for an independent, comprehensive technology due diligence conducted specifically for the M&A context.

The question to ask before commissioning any technical assessment in an M&A process is simple: is this designed to tell me what I need to know to make this deal decision — or is it designed to tell me whether this system meets a standard? If it is the latter, it is not technology due diligence.

At VeryDiligent, every engagement is designed specifically for the M&A context — investigation-led, commercially focused, and structured to give investors and acquirers the complete technical picture they need to make confident decisions.

Contact us today to discuss your upcoming transaction.

Related reading: Technology Due Diligence, Technical Due Diligence, IT Due Diligence, Code Review: What’s the Difference? | Why Most Technology Due Diligence Misses the Real Risks | Our Framework for Technology Due Diligence Explained