Vendor security is a two-sided coin for startups. On one side, your enterprise customers will evaluate your security before signing a deal. On the other, you need to evaluate the security of your own third-party tools and services. Both sides matter — and both can make or break deals.
Why Vendor Security Matters
Supply chain attacks are now one of the top attack vectors. A breach at a single vendor can expose data across hundreds of customers. Enterprise buyers know this, which is why vendor security reviews have become thorough and non-negotiable. If you can’t demonstrate solid security practices, you’ll lose deals to competitors who can.
Part 1: Passing Vendor Security Reviews
When an enterprise prospect evaluates your startup, they’ll typically send a security questionnaire or request documentation. Here’s how to be ready.
Common security questionnaires
- SIG (Standardized Information Gathering) — A comprehensive questionnaire from Shared Assessments, covering 18 risk domains
- CAIQ (Consensus Assessments Initiative Questionnaire) — Cloud-focused, published by the Cloud Security Alliance
- Custom questionnaires — Many enterprises have their own. These often overlap 70–80% with SIG/CAIQ
- VSA (Vendor Security Alliance) — A streamlined questionnaire designed for SaaS companies
What reviewers look for
Regardless of the questionnaire format, reviewers evaluate:
- Data handling — How you collect, store, process, and delete customer data
- Access controls — MFA, RBAC, least privilege, and offboarding procedures
- Encryption — At rest and in transit, key management practices
- Incident response — Documented plan, breach notification timelines
- Business continuity — Backups, disaster recovery, uptime commitments
- Compliance certifications — SOC 2, ISO 27001, or equivalent
- Sub-processor management — How you evaluate your own vendors
How to prepare
- Get SOC 2 or ISO 27001: A certification or audit report answers 60–70% of questionnaire questions upfront
- Maintain a security page: Publish your security practices at a public URL (e.g., complara.io/security)
- Pre-fill a SIG or CAIQ: Keep a completed version on hand to speed up reviews
- Build an evidence library: Screenshots of MFA settings, encryption configs, access reviews, and policy documents. Use Complara to keep evidence organized by checklist item
- Document your sub-processors: List every third-party tool that processes customer data, with their security posture noted
Part 2: Managing Your Own Vendor Risk
As a startup, you rely on dozens of third-party tools. Each one is a potential risk. Here’s how to build a practical vendor risk management program.
1. Inventory your vendors
List every SaaS tool, cloud service, API, and contractor that accesses your systems or data. Categorize them by data sensitivity: critical (accesses customer data), moderate (accesses internal data), low (no data access).
2. Assess risk by tier
- Critical vendors: Request SOC 2 report, review their security documentation, sign a DPA if they process personal data
- Moderate vendors: Review their published security page and certifications
- Low-risk vendors: Basic check that they have reasonable security practices
3. Collect and review documentation
For critical vendors, collect: SOC 2 Type II reports (review annually), penetration test summaries, data processing agreements, insurance certificates, and incident history.
4. Review annually
Vendor risk isn’t a one-time exercise. Re-assess critical vendors at least annually. Check for: new incidents, changes to their security posture, sub-processor changes, and contract renewals.
Frequently Asked Questions
How long do vendor security reviews take?
If you’re well-prepared (SOC 2 report + pre-filled questionnaire + evidence library), a review takes 1–2 weeks. Without preparation, expect 4–8 weeks of back-and-forth.
Do I need a vendor risk program if I’m a small startup?
Yes. SOC 2 and ISO 27001 both require vendor management. Even without a certification, managing vendor risk protects your customers’ data and your reputation.
What’s the fastest way to pass a security review?
Get SOC 2 Type II certified. It pre-answers the majority of questionnaire questions and signals maturity to reviewers. Track your progress with Complara’s vendor security checklist.