The deal-math that decides it
Startups should treat this as pipeline arithmetic, not philosophy. Count the deals in your pipeline where a security review, questionnaire, or tender mentions ISO 27001 (or "certified ISMS"). Multiply by average contract value. Compare against a realistic program cost: certification fees in the low five figures over three years, plus meaningful internal time, plus optional tooling. For most B2B SaaS startups with even one enterprise logo in play, the math closes fast, and the certificate keeps paying because it answers hundreds of future questionnaires with a single scoped document.
What it costs a small team in truth
Money is the smaller half. The real cost is founder and engineer attention across 4 to 8 months: risk assessment, control implementation, access reviews, evidence habits, an internal audit, and a management review. The compensating truth: a 15-person cloud-native startup has a small attack surface and can inherit much infrastructure control from its cloud provider, so a precisely scoped ISMS is genuinely lightweight. The standard's documentation demands are risk-proportionate; a startup ISMS should look like a startup, not a bank.
ISO 27001 or SOC 2 first
Let your customers' geography decide: US enterprise buyers default to asking for SOC 2 Type II; European, Asian, government, and global-supply-chain buyers default to ISO 27001. If the pipeline is mixed or undecided, ISO 27001 first is the durable choice: it builds the management system both frameworks need, its certificate lasts three years against SOC 2's annual report cycle, and extending a real ISMS to SOC 2 later is incremental work. Whichever you choose, build one control set serving both; parallel programs are the classic startup compliance money-fire.
If you decide to wait
Waiting is legitimate; being unprepared is not. Do now, for almost nothing: SSO and MFA everywhere, offboarding checklists, least-privilege access with quarterly reviews, encrypted laptops, dependency scanning in CI, an incident channel with a named owner, and a one-page risk register leadership actually reads. That kernel protects you today and converts to certification in months, not quarters, when the first big deal demands it. The startups that suffer are the ones that discover ISO 27001 inside a procurement deadline with none of the habits in place.