SIG Lite: Streamlined Vendor Assessment Explained

What SIG Lite Covers?

SIG Lite covers the same 18 risk domains as the full SIG:

How SIG Lite Differs from the Full SIG?

The difference between SIG Lite and the full SIG is depth, not breadth. Both cover the same domains. The distinction is in the level of granularity.

Full SIG example (Access Control domain):

The full SIG might include questions like:

• Do you enforce multi-factor authentication for all remote access?
• What MFA methods are supported (hardware token, software token, biometric, SMS)?
• Is MFA enforced for privileged accounts accessing production systems?
• How frequently are access privileges reviewed for privileged accounts?
• What is your process for revoking access upon employee termination?
• What is the maximum time between termination and access revocation?
• Do you maintain a formal access control policy? When was it last reviewed?
• How are service accounts managed and reviewed?
• Do you enforce session timeouts? What are the timeout values?

SIG Lite example (same domain):

SIG Lite would consolidate this into higher-level questions like:

• Do you enforce multi-factor authentication for remote and privileged access?
• Do you have a formal process for access provisioning, review, and revocation?
• Do you maintain and enforce an access control policy?

The SIG Lite questions cover the same control objectives but accept a higher-level response. This is appropriate for vendors where you need reasonable assurance but do not require the granular detail that a critical vendor assessment demands.

What SIG Lite Catches

SIG Lite is effective at identifying:

• Missing fundamental controls. Vendors without basic security hygiene — no MFA, no encryption, no incident response plan — will be flagged by SIG Lite just as readily as by the full SIG.
• Absent security governance. SIG Lite covers policy existence, organizational accountability, and risk management frameworks. Vendors without these foundations will be apparent.
• Regulatory compliance gaps. SIG Lite asks about compliance with relevant regulations and frameworks, surfacing vendors that have not addressed their regulatory obligations.
• Business continuity gaps. SIG Lite covers disaster recovery and business continuity planning at a level sufficient to identify vendors with no resilience planning.

What SIG Lite May Miss

SIG Lite's higher-level questions may not surface:

• Implementation details. A vendor might confirm they "enforce MFA" but SIG Lite will not reveal that they only enforce it for a subset of users or that they allow SMS-based MFA, which is vulnerable to SIM swapping.
• Maturity nuances. The difference between a vendor with a mature, tested incident response program and one with an incident response document that has never been exercised may not emerge from SIG Lite's questions.
• Technical architecture specifics. Detailed questions about network segmentation, encryption algorithms, key management procedures, and application security testing methodologies are largely absent from SIG Lite.
• Subprocessor details. SIG Lite asks about third-party risk management at a high level but does not probe deeply into subprocessor assessment practices and supply chain risk management.

This is precisely why SIG Lite is appropriate for lower-risk vendors: the additional detail that the full SIG captures is most valuable for vendors where the consequence of a control failure is highest.

Where does SIG Lite fit in a vendor risk program?

Effective vendor risk programs match assessment rigor to vendor risk. SIG Lite fits squarely in the middle of a tiered assessment strategy.

Tier 2 Vendors: The SIG Lite Sweet Spot

Tier 2 vendors are the primary use case for SIG Lite. These are vendors that have meaningful access to your environment or data but are not in the critical tier that warrants a full SIG assessment.

Common Tier 2 vendor examples:

• CRM platforms (Salesforce, HubSpot) — handle customer contact information and deal data
• HR and payroll platforms (Workday, Gusto) — process employee PII and financial data
• Marketing automation (Marketo, Mailchimp) — access customer email addresses and engagement data
• Project management (Jira, Asana) — may contain product roadmaps and internal communications
• Analytics platforms (Amplitude, Mixpanel) — process user behavioral data
• Communication tools (Slack, Teams) — contain internal discussions and potentially sensitive information

For these vendors, SIG Lite provides enough depth to identify material security gaps while respecting the proportionality principle: the assessment effort should be proportional to the risk.

Tier 3 Vendors: SIG Lite as the Maximum

For Tier 3 vendors, SIG Lite represents the upper bound of assessment rigor. Many organizations use an even lighter approach for Tier 3 — a self-attestation form of 20 to 40 questions covering only the essentials. But if you prefer a standardized instrument for all vendors, a scoped SIG Lite (with irrelevant domains marked as out of scope) provides a reasonable option.

Implementing SIG Lite in Your Program

Step 1: Define Your Tiering Criteria

Before deploying SIG Lite, you need clear criteria for which vendors fall into each tier. The criteria should be based on objective, measurable factors:

• Data sensitivity. What classification of data does the vendor access?

Step 2: Scope the Assessment

Not all 18 SIG Lite domains will be relevant for every vendor. Before distributing the questionnaire, scope the assessment by identifying which domains apply:

• A cloud-only SaaS vendor may have physical security marked as out of scope
• A vendor that does not process personal data may have the privacy domain reduced or excluded
• A vendor with no endpoint access to your network may have endpoint device security excluded

Scoping reduces the burden on the vendor and focuses your review on the domains that matter for the specific relationship.

Step 3: Distribute and Collect

SIG Lite is distributed as an Excel workbook, similar to the full SIG. Best practices for distribution:

Step 4: Review and Assess

When the completed SIG Lite is returned, review it with these priorities:

1. Look for absent controls first. Any "No" answer on a fundamental control (MFA, encryption, incident response) should trigger follow-up regardless of vendor tier.
2. Check for consistency. Answers should be internally consistent — a vendor claiming strong access controls but no formal access control policy is a red flag.
3. Validate against SOC 2 report. If the vendor provides a SOC 2 report, cross-reference key SIG Lite answers against the report's control descriptions and testing results.
4. Identify follow-up areas. SIG Lite's higher-level questions may surface areas where you need more detail. Document these and follow up directly rather than escalating to a full SIG.

Step 5: Document and Track

Record the assessment results in your vendor risk register:

• Assessment date and SIG Lite version used
• Domains in scope and out of scope
• Key findings and risk ratings
• Remediation requests and due dates
• Next reassessment date
• Risk acceptance decisions (if applicable)

Common Questions About SIG Lite

Can I Start With SIG Lite and Escalate to Full SIG?

Yes, and this is a pattern we recommend. If a SIG Lite assessment surfaces concerns that require deeper investigation, escalate to the full SIG for the specific domains in question. You do not need to redo the entire full SIG — just the domains where SIG Lite identified potential gaps.

This is also useful when a vendor's tier changes. A Tier 2 vendor that expands their scope to handle sensitive data should be re-tiered to Tier 1 and reassessed with the full SIG.

Should Vendors That Hold SOC 2 Still Complete SIG Lite?

In our experience, yes — but with a lighter touch. A SOC 2 Type II report covers many of the same controls that SIG Lite assesses, so you can accept the SOC 2 report as evidence for most answers. The value of completing SIG Lite alongside the SOC 2 review is coverage of domains that SOC 2 may not address in depth: physical security, HR practices, regulatory compliance, and business continuity planning.

What we tell clients is to let the vendor reference their SOC 2 report in their SIG Lite responses rather than re-describing controls that are already documented in the report.

How Often Should SIG Lite Assessments Be Refreshed?

In between assessments, continuous monitoring through security rating platforms and breach notification feeds provides ongoing visibility.

Any vendor should be reassessed immediately following a material event: a reported security incident, a major infrastructure change, a change in the data they process, or a change in your risk tiering criteria.

Is SIG Lite Accepted by Auditors?

SOC 2 auditors look for evidence that you have a risk-based vendor assessment program. Using SIG Lite for Tier 2 and Tier 3 vendors — with documented rationale for why a lighter assessment is appropriate — is fully consistent with audit expectations. What auditors do not want to see is the same assessment instrument applied uniformly regardless of risk, or conversely, an absence of assessment for lower-tier vendors.

The key is documentation. If your vendor risk policy defines tiering criteria and specifies assessment instruments by tier, and your records show consistent execution against that policy, auditors will find your program satisfactory.

SIG Lite vs Other Lightweight Assessments

How does SIG Lite compare to other streamlined assessment options?

SIG Lite's advantage over other lightweight instruments is its breadth: 18 domains ensure no major risk area is missed. Its advantage over a custom self-attestation is standardization: consistent format, consistent questions, and alignment with the broader SIG ecosystem.

For more on how CAIQ compares to SIG for cloud vendor assessments, see our CAIQ vs SIG analysis. For a broader overview of all major questionnaire formats, see our security compliance questionnaires guide.

AICPA & CIMA’s SOC overview describes CPA assurance services. It defines the assurance context; it does not establish vendor rankings, market prices, or a particular company’s readiness.