Invest when growth or risk makes it necessary. Triggers: moving upmarket to enterprise, handling regulated data (personal, health, payments), scaling outbound marketing, or preparing for diligence (SOC 2/ISO). Pick a lightweight baseline, automate evidence early, and build only what buyers and risk demand.

Pick the framework buyers expect and your risks demand. U.S. SaaS often starts with SOC 2; global enterprise favors ISO 27001. Add sector rules (HIPAA, PCI, GLBA) only if you handle that data. Use NIST CSF or CIS as your practical baseline. Map data flows, avoid over-scope, and automate evidence.