ISO 27001 vs. SOC 2: Which Should Your Company Do First?

Sooner or later a large customer sends a security questionnaire or asks for proof of your security program. The next question is usually which framework to pursue. Both SOC 2 and ISO 27001 are well respected. The right first choice depends mostly on who you sell to.

The key differences

• What you receive

  SOC 2 produces a detailed report from an independent CPA firm. ISO 27001 produces a certificate from an accredited certification body, with a statement of which controls apply.

• What it examines

  SOC 2 tests your controls against the AICPA Trust Services Criteria. Security is required, while availability, processing integrity, confidentiality and privacy are optional. ISO 27001 requires a full information security management system, with risk-based selection of controls from Annex A.

• Time frame

  A SOC 2 Type I looks at control design at one point in time, and a Type II tests operation over a period, often 3 to 12 months. ISO 27001 certificates run for three years, with surveillance audits each year.

• Where it is expected

  SOC 2 is common among US buyers, especially for SaaS. ISO 27001 is often preferred in Europe, the Middle East, Asia and in global enterprises.

How to decide

• Choose SOC 2 first if

  Most of your pipeline is North American, your buyers want to read a detailed report, and you sell software or services that handle customer data.

• Choose ISO 27001 first if

  You sell internationally, your buyers ask for a certificate by name, or you want a formal management system across the whole company.

• Plan for both if

  You serve large enterprises in several regions. Map controls once and collect evidence once, so you can reuse most of the work.

What overlaps

Access reviews, change management, incident response, vendor management, risk assessment, logging, backups and security training appear in both. Build these controls once with clear owners and automated evidence where possible. What ISO adds is mainly management system discipline: formal scope, risk treatment, internal audit and management review.

What SOC 2 looks like in practice

A SOC 2 report is a detailed document for customers to read, usually shared under a non-disclosure agreement. It includes the auditor's opinion, a description of your system, the controls you operate, the tests the auditor performed and the results. Buyers often go straight to the exceptions section, so write clear responses to any exceptions that appear.

Most companies start with a Type I or move directly to a Type II if buyers will accept waiting. Type II is what larger customers normally want, since it shows that controls worked over time. Reports are usually renewed every year. If a customer asks for assurance between reports, you can provide a bridge letter, which is your own statement that nothing material has changed. A SOC 3 is a shorter general report that can be shared publicly, but it does not replace the detail in SOC 2.

What ISO 27001 looks like in practice

ISO 27001 asks you to run an information security management system, often shortened to ISMS. In practice, that means defining what is in scope, assessing risks, deciding how to treat them, measuring whether controls work, auditing yourself and having management review the results. The current version, ISO/IEC 27001:2022, lists 93 reference controls in Annex A, grouped into organizational, people, physical and technological themes.

Your Statement of Applicability records which controls apply and why. Certification normally has two audit stages. Stage 1 reviews your documentation and readiness, and Stage 2 tests whether the system really operates. Check that your certification body is accredited by a recognized accreditation organization, as some buyers will ask, and a certificate from an unaccredited provider may carry little weight.

Decide your scope carefully

Scope has a large effect on cost, effort and how useful the result is. Too narrow, and customers may find that the product they buy is not covered. Too wide, and you take on controls for parts of the business buyers do not care about.

• Start from what customers buy

  Include the production systems, data and teams behind the service in your contracts.

• Include supporting functions

  HR, IT, engineering and support usually contribute controls, even when they are not the product itself.

• Consider your vendors

  Cloud providers and other subservice organizations need to be reviewed. Collect their reports and note the controls they expect you to perform.

• Choose SOC 2 criteria deliberately

  Security is required. Add availability or confidentiality if customers rely on them, rather than choosing every category by default.

A realistic path to your first audit

• Readiness review

  Compare current practices with the framework, and list what is missing. Be honest here, because auditors will find the gaps anyway.

• Fix the basics

  Address access reviews, MFA, offboarding, change control, logging, backup testing and vendor records. These are common sources of findings.

• Write useful policies

  Keep them short and accurate. An auditor will test whether you do what your policy says, so never copy a template that does not match how you work.

• Operate and collect evidence

  Run the controls and retain proof, such as tickets, access reviews and training records. Automation can help, but someone must still own each control.

• Run an internal check

  Test a sample yourself. This is required for ISO 27001 and valuable for SOC 2.

• Complete the audit

  Choose the auditor early, so you can agree scope and timing. Your auditor must remain independent from whoever prepared your controls.

Common mistakes to avoid

The most expensive mistake is buying a framework before asking customers what they need. Look through recent security questionnaires and lost deals first. A second is treating compliance as a one-time project: SOC 2 Type II and ISO surveillance audits both expect controls to keep operating, so missed quarterly reviews can become findings later.

Finally, do not confuse a passed audit with complete security. Both frameworks show that you run a managed set of controls, but an attacker does not check your report. Use the audit work to reduce real risks, such as phishing, exposed cloud assets and weak access, and the certificate or report will mean more to the buyers who read it.

Where NPLUS Global helps

We carry out the gap assessment, map controls across both frameworks, write the policies and prepare your evidence for the auditor. The audit itself is performed by an independent firm, which we help you select and work with.