SOC 2 or ISO 27001: which one should you actually do first?

SOC 2 and ISO 27001 are often framed as rivals. They are more like two accents of the same language. Both are about proving you manage information security seriously. They just come from different places and speak to different rooms.

The one-line difference that actually matters

SOC 2 is an attestation: an independent CPA writes a report giving their opinion on your controls against the Trust Services Criteria. ISO 27001 is a certification: an accredited body certifies that your Information Security Management System meets the standard. In the room, that difference shows up as geography. SOC 2 is the reflex ask from US buyers. ISO 27001 is the passport that travels across Europe and APAC without a translator.

Do not ask which is better. Ask which one your next three buyers will name. That is the one that is better, for you, right now.

How to choose in practice

• Mostly US customers, SaaS: start with SOC 2. It is what their security teams expect to see.
• International or enterprise-heavy pipeline: start with ISO 27001. One certificate, recognised almost everywhere.
• Both kinds of buyer already knocking: pick whichever is blocking the bigger deal, and know the second one is now mostly downhill.

The secret nobody tells you: they overlap enormously

The control sets share a huge amount of DNA. Access control, change management, incident response, risk assessment, vendor management. Do one properly and you have done most of the other. This is where a platform earns its keep: Compliance One models your controls once and maps the shared evidence across both, so the second framework is largely a matter of filling gaps, not starting over. Many teams do SOC 2 to unblock US deals, then add ISO 27001 for the international pipeline, and are pleasantly surprised how little new work the second one takes. Rivals? No. More like a two-for-one you did not know you were buying.