ISO 27001 vs SOC 2: Which Certification Should You Pursue First?

If a prospect has just asked for your “security certification,” you are probably weighing ISO 27001 against SOC 2. Both signal that you take information security seriously. But they were built by different bodies, for different audiences, and they prove subtly different things — so picking the wrong one first can cost you a sales cycle or a wasted audit.

This guide breaks down what each actually certifies, who tends to ask for which, the realistic cost and timeline, and a simple decision framework for choosing one — or running both with minimal duplicate effort.

The one-line difference

ISO 27001 certifies that you have a working information security management system (ISMS) — a governance machine that continually identifies risk and manages controls. SOC 2 is an attestation report in which an independent auditor describes your controls and tests whether they operated effectively against five Trust Service Criteria.

Put simply: ISO 27001 is an internationally recognised certificate; SOC 2 is a detailed report a customer’s security team will actually read.

Who asks for which?

The single most useful thing you can do is ask your last five lost or stalled deals which one they wanted. Let demand, not preference, drive the decision.

Cost and timeline, realistically

Both are achievable in three to six months for a focused team. SOC 2 Type I can be quicker because it is a point-in-time design assessment, while SOC 2 Type II and ISO 27001 both require an observation window during which your controls must demonstrably operate.

The bulk of the cost is rarely the auditor — it is the internal time spent writing policies, collecting evidence, and remediating gaps. That is exactly the work automation removes, which is why the tooling you choose matters as much as the framework.

A simple decision framework

The good news: they overlap heavily

You do not have to choose forever. ISO 27001’s Annex A controls and SOC 2’s Trust Service Criteria cover a great deal of the same ground — access control, change management, vulnerability management, incident response, vendor risk, and monitoring. Once you have built the evidence base for one, the second is largely a mapping exercise rather than a fresh start.

This is where a control library that maps a single piece of evidence to multiple frameworks pays for itself: you collect once and satisfy both. If you are just beginning, our ISO 27001:2022 implementation guide and SOC 2 guide for startups walk through each path in detail.

The bottom line

There is no universally “better” certification — only the one your buyers are asking for. Choose based on where your revenue comes from, build the evidence once, and treat the second framework as an extension of the first. Done well, the second audit costs a fraction of the time of the first.