SaaS Security Checklist for B2B Founders
Selling software to businesses means your security becomes part of theirs. Enterprise buyers will ask detailed questions, and attackers will target the data of every customer at once. This checklist covers what B2B SaaS products need.
Tenant isolation
Cross-tenant data exposure is the worst-case SaaS vulnerability: one customer seeing another's data.
- Every query is scoped by tenant, enforced centrally.
- Database-level protections, such as row-level security or separate schemas, as a backstop.
- File storage paths and pre-signed URLs scoped per tenant.
- Search indexes, caches and analytics separated or filtered by tenant.
- Background jobs and exports run with the correct tenant context.
- Automated tests that verify tenant A cannot access tenant B.
Identity and access
- SSO via SAML or OIDC for customers, a common enterprise requirement.
- SCIM provisioning for larger customers.
- MFA for all users, enforceable by organisation admins.
- Granular roles, at minimum admin, member and read-only.
- Session controls, such as timeouts configurable by customers.
Audit logging
- Logs of logins, permission changes, data exports and admin actions.
- Customer-facing audit log access for enterprise plans.
- Logs retained and protected from tampering.
Data protection
- Encryption in transit everywhere and at rest for databases, backups and files.
- Clear data retention and deletion on contract end.
- A published list of subprocessors.
- Data residency options if selling into regions that require them.
Application security
- Regular penetration testing with authenticated, multi-tenant coverage.
- Dependency and secret scanning in CI.
- Secure code review for sensitive changes.
- A vulnerability disclosure policy and
security.txt.
Infrastructure
- Least-privilege cloud IAM, with no long-lived keys where avoidable.
- Production access limited, logged and ideally just-in-time.
- Separate environments for development, staging and production.
- Backups tested regularly.
Operations
- An incident response plan with customer notification commitments.
- On-call alerting for security events.
- Employee security basics: MFA, device management, onboarding and offboarding.
Compliance and trust
- SOC 2, ISO 27001, or a credible roadmap.
- A security page or trust centre on your website.
- A security overview document and answer library for questionnaires.
- A current pentest summary to share with prospects.
The enterprise-readiness scorecard
| Area | Minimum | Enterprise-ready |
|---|---|---|
| Tenant isolation | App-level scoping | Plus DB-level enforcement and tests |
| Identity | Email and password with MFA | SSO, SCIM, enforced MFA |
| Logs | Internal logs | Customer-facing audit logs |
| Testing | Annual pentest | Continuous testing plus annual report |
| Compliance | Security overview | SOC 2 Type 2 or ISO 27001 |
Testing tenant isolation
Tenant isolation is where SaaS testing matters most, and where traditional scanners are blind. SecurityInfinity tests with accounts in multiple tenants and roles, verifies any cross-tenant access, and produces a report you can share with enterprise buyers. Get a pentest report.
Frequently asked questions
Do we need SSO to sell to enterprises?
Many enterprise buyers require it. Even if not mandatory, it often speeds procurement.
What is the most common SaaS vulnerability?
Broken access control, especially IDOR and cross-tenant data access.
When should a SaaS startup get SOC 2?
Usually when enterprise deals start requiring it. Preparing earlier, with good controls and testing, makes the audit faster.