If you have been through SOC 2 and then started ISO 27001, you will have noticed that you are answering the same questions again in a different vocabulary. That is not a coincidence, and it is the single largest available saving in a multi-framework program.
The frameworks are not as different as their documents
Every one of these frameworks is trying to establish the same handful of things: that you know what you have, that you control who can reach it, that you would notice if something went wrong, and that you have decided in advance what to do when it does.
Access control is the clearest example. Consider one requirement, that access is granted on the basis of role and reviewed periodically:
| Framework | Where it lives |
|---|---|
| SOC 2 | CC6.1, CC6.2, CC6.3 |
| ISO 27001 | A.5.15, A.5.18 |
| HIPAA | §164.308(a)(4) |
| PCI DSS | Requirement 7 |
Four references, four vocabularies, one piece of evidence: your access review, with its scope, its date, and the changes it produced.
What "mapping" actually means
Mapping is not translating the requirement text. It is identifying the evidence artifact that satisfies more than one requirement, and then producing that artifact once.
The unit of reuse is the artifact, not the control. This matters because two frameworks can describe the same control and still want different evidence: one wants the policy, the other wants proof the policy was followed.
Artifact: Q2 user access review (export + reviewer sign-off + remediation tickets)Satisfies: SOC 2 CC6.2 · ISO 27001 A.5.18 · HIPAA §164.308(a)(4)(ii)(C)Where the overlap breaks down
Overlap is real but it is not total, and the exceptions are where teams get caught out.
HIPAA is narrower and more specific. It cares about protected health information in particular, and several of its requirements have no analogue elsewhere.
PCI DSS is prescriptive where the others are risk-based. SOC 2 asks whether your approach is appropriate; PCI DSS tells you the answer, sometimes down to a configuration value.
ISO 27001 requires a management system, not just controls. The Statement of Applicability, the risk methodology and the management review have no SOC 2 equivalent at all.
A sensible order
If you are choosing which to do first and have a free choice:
SOC 2 if your buyers are North American software companies.
ISO 27001 if they are European or enterprise, or if you expect to need both eventually: the management system is the expensive part, and building it first means SOC 2 largely falls out of it.
HIPAA or PCI DSS when a specific customer or payment flow requires it. Neither is a general-purpose trust signal in the way the first two are.
You will see claims that one framework gives you a specific percentage of another. Treat any such number as a rough planning aid rather than a fact: the real overlap depends entirely on your scope, and the arithmetic behind published figures is rarely shown. ::
The practical takeaway
Do the mapping work before the second framework, not during it. The saving comes from having collected reusable evidence all along, and evidence you did not collect at the time is evidence you cannot reuse.