Why and When You Look at a Fourth Party’s SOC Report
Sep 17, 2025
In today's increasingly interconnected digital landscape, companies no longer rely solely on their own systems or even their direct third-party vendors. Instead, they’re operating within extended supply chains that include fourth parties—the vendors of their vendors. With cyber threats escalating and regulatory compliance becoming more demanding, it's no longer enough to stop your security due diligence at the third-party level. You must also consider the SOC reports of these fourth parties.
But why does this matter? And when is it appropriate—or even critical—to request and review a fourth party’s SOC report?
What is a Fourth Party?
A fourth party is any external service provider used by your third-party vendors. For instance, if your cloud-based payroll system is managed by a third party that hosts it on Amazon Web Services (AWS), then AWS is your fourth party. You’re still exposed to the risks and vulnerabilities of that fourth party, even if you never directly interact with them.
Why Fourth Party SOC Reports Matter
Most organizations understand the importance of reviewing SOC 2 reports for third-party vendors. These reports provide insights into how a service provider manages data security, availability, processing integrity, confidentiality, and privacy. However, if your third party relies on a fourth party whose controls are weak or non-compliant, your data may still be at risk.
Here’s why fourth-party SOC reports matter:
Chain of Trust
Your data security is only as strong as the weakest link in your vendor chain. Even if your third party is secure, a vulnerable fourth party could open the door to a cybersecurity breach.Regulatory Compliance
Frameworks like GDPR, HIPAA, and ISO 27001 hold companies responsible for how their data is managed—not just by them, but by anyone who handles it on their behalf. Regulatory auditors may ask for evidence that you’ve evaluated your extended vendor ecosystem.Incident Response Planning
If a data breach occurs, understanding the fourth-party landscape will help you determine where the vulnerability lies and how to respond. Reviewing SOC reports in advance equips your team with preparedness and accountability.Vendor Risk Management (VRM)
A robust VRM strategy should extend beyond direct vendors. Tools like SkyBlackBox help companies gain visibility into fourth-party relationships, enabling more comprehensive risk assessments.
When Should You Look at a Fourth Party’s SOC Report?
Not all fourth parties warrant a deep dive. So, when should you dig into a fourth party’s SOC 2 report?
1. When the Fourth Party Has Access to Sensitive Data
If a fourth party stores, processes, or transmits your customer data, it’s crucial to evaluate their security controls. You don’t want a blind spot that could result in data loss or compliance violations.
2. When Your Third Party Relies Heavily on a Specific Provider
If your third-party vendor is merely a layer over another service provider (e.g., reselling a SaaS solution), you should investigate that fourth party’s SOC report directly.
3. When There’s a History of Security Incidents
If a fourth party has experienced cyber incidents, breaches, or downtime in the past, you should be proactively reviewing their security posture before continuing your reliance on them.
4. When You’re in a Regulated Industry
Industries like finance, healthcare, and government contracting often require stricter due diligence. In such cases, ignoring fourth-party risks could result in fines, penalties, or reputational damage.
5. When Using a Platform Like SkyBlackBox
If you use a vendor risk intelligence tool like SkyBlackBox, it will often surface fourth-party connections automatically. This visibility allows your team to take action—reviewing SOC reports, requesting attestations, or escalating concerns.
How SkyBlackBox Helps Manage Fourth-Party Risk
One of the most effective ways to track fourth-party relationships is through tools like SkyBlackBox, a risk intelligence platform that helps organizations:
Map their entire vendor ecosystem, including fourth and nth parties
Monitor changes in SOC 2 reports, compliance status, and risk ratings
Set alerts when critical changes occur in a vendor’s security posture
Automate due diligence workflows to save time and reduce manual tracking
With SkyBlackBox, you can transform your reactive risk management into a proactive strategy that addresses both direct and indirect threats.
Final Thoughts
The era of isolated risk assessments is over. In a world of shared services and cloud dependencies, understanding the full scope of your vendor chain—including fourth parties—is not just best practice. It’s a necessity.
By knowing when and why to review a fourth party’s SOC report, and leveraging tools like SkyBlackBox, you can build a more resilient, secure, and compliant digital ecosystem.