How to Automate Vendor Access Control Evidence for SOC 2 and ISO 27001

Documenting third-party access is usually the messiest part of an audit. You can easily pull a list of internal employees from your identity provider, but vendor access management often happens outside of those systems. A contractor gets invited directly to a GitHub repository. An external pentester gets temporary AWS read access. Proving these external accounts are managed correctly for SOC 2 and ISO 27001 requires actual evidence. Usually, that means taking manual screenshots of guest user panels across your entire tech stack. Automating this documentation ensures your access controls are consistently verified without spending hours grabbing screenshots before the auditor arrives.

What Evidence Do Auditors Require for Vendor Access Management?

Auditors expect to see your approved vendor list, the security review for each vendor, and technical proof that third-party access to your systems is restricted to least privilege.

For SOC 2, this falls under CC6.1 (Logical Access) and CC9.2 (Vendor Risk Management). For ISO 27001, you are looking at A.5.15 (Access Control) and A.5.19 through A.5.23 (Supplier Relationships).

The documentation required breaks down into two categories: design (the policy) and operating effectiveness (the technical proof).

Control Area	Framework ID	Required Evidence
Vendor Approval	SOC 2 CC9.2 ISO 27001 A.5.19	Signed contracts, completed security questionnaires, or SOC 2 reports from the vendor, plus the internal Jira ticket showing approval.
Logical Access	SOC 2 CC6.1 ISO 27001 A.5.15	Screenshots of application admin panels showing external users, their assigned roles, and their restricted permissions.
Access Reviews	SOC 2 CC6.1 ISO 27001 A.5.18	Documentation showing that a manager reviewed the list of external contractors and confirmed their access is still required.
Offboarding	SOC 2 CC6.1 ISO 27001 A.5.15	Audit logs or screenshots proving a contractor's access was revoked immediately upon contract termination.

Honestly, auditors know that contractor access is where most companies drop the ball. They will specifically ask for a sample of external users to test if your offboarding procedures actually work in practice.

Where Traditional Compliance Automation Stops for Vendor Access

Most companies try to automate this process using standard GRC platforms. This works perfectly for your full-time employees. Tools like Drata or Vanta connect to Okta or Google Workspace via API, read your employee list, and check if everyone has MFA enabled.

But third-party access rarely lives cleanly in your IdP.

When your engineering team hires a freelance developer for three weeks, they don't always create a corporate email address for them. They just invite the developer's personal GitHub account (dev-contractor-99) directly to a specific repository.

Because APIs rely on mapping accounts back to your central HR directory, they struggle with these orphaned external accounts. The GRC tool will either ignore the guest user entirely or throw an "Unmapped Account" error that you have to manually resolve.

To prove to an auditor that dev-contractor-99 only has read access to one specific repository, APIs aren't enough. You have to log into GitHub, navigate to the repository settings, go to the "Collaborators and teams" tab, and take a screenshot showing exactly what permissions that user holds.

How Do You Automate Third-Party Access Control Evidence?

You automate third-party access evidence by using AI agents to capture the actual user interface of your applications, rather than relying solely on APIs.

Instead of an engineer spending a Friday afternoon logging into AWS, GitHub, Jira, and Zendesk to take screenshots of guest users, an AI agent navigates to those specific admin panels. It captures screenshots of the external collaborator lists, verifies the permission levels, and generates a PDF evidence pack.

This approach solves the "unmapped account" problem. The agent simply records exactly what the auditor would see if they were sitting next to you looking at your screen. It captures the user's handle, their role (e.g., "Guest" or "Read-Only"), and the timestamp of the capture.

This visual evidence is exactly what auditors expect during a SOC 2 Type 2 observation period, and it proves your vendor access management controls are operating effectively without manual intervention.

How Do You Prove Vendor Offboarding?

Vendor offboarding is highly scrutinized during audits because lingering access is a massive security risk. When a contractor finishes their project, you need evidence that their access was terminated.

For internal employees, you just provide the Okta deprovisioning log. For external vendors, the evidence collection is more difficult. You need one of two things:

A system audit log showing the exact timestamp when the guest user was removed from the application.
A point-in-time screenshot of the current user list, cross-referenced against the terminated vendor list, proving they are no longer present.

If the application doesn't export clean JSON audit logs for user removal (which many basic SaaS tools do not), you are stuck with the screenshot method. By automating UI captures on a weekly or monthly schedule, you build a continuous visual audit trail. When the auditor selects a terminated contractor for their sample, you simply hand them the automated screenshot pack from the week their contract ended, proving they were removed from the system.

What About the Vendor Security Reviews?

Technical access is only half of the vendor control requirement. You also have to prove you evaluated the vendor's security posture before giving them access to your data.

For SOC 2 CC9.2, this means collecting SOC 2 reports from your critical vendors or having them fill out a security questionnaire.

The mistake most teams make is storing the vendor's SOC 2 report in a random Google Drive folder. The auditor doesn't just want the report; they want evidence that you actually read it and approved it.

The easiest way to document this is to create a Jira ticket for every new vendor. Attach their SOC 2 report to the ticket, add a comment stating "Reviewed vendor SOC 2, no critical exceptions noted," and have the CTO or security lead transition the ticket to "Approved."

You can then use automated evidence collection to capture a screenshot of that Jira ticket. The ticket shows the date, the approver, and the attached documentation all in one verifiable artifact.

Learn More About Continuous Compliance

For a complete guide to unifying your audit documentation, see our guide on automating continuous evidence collection across SOC 2, ISO 27001, HIPAA, and CMMC, including how to capture application-level controls that APIs miss.