Penetration Testing Requirements for Vendors: What Operations and IT Actually Need to Decide

Most companies ask vendors about penetration testing because an auditor expects the question, not because they have decided what an acceptable answer looks like. The result is predictable: documents get exchanged, assurances get logged, and no one can say with confidence whether risk actually changed. Penetration testing requirements exist to force specificity where reassurance is cheap, by defining what testing must cover, how often it happens, who reviews the results, and how findings turn into action instead of static evidence.

Define Why Vendor Penetration Testing Exists

Vendor penetration testing requirements fail most often because their purpose is left implicit, which turns the request into a trust exercise rather than a control. Vendors respond by optimizing for reassurance instead of relevance, providing artifacts that look complete while answering the wrong questions.

The purpose should be stated plainly. Penetration testing exists to reduce uncertainty about how a vendor's systems behave under realistic attack conditions, especially where those systems touch your data, your customers, or your fulfillment commitments. It is not meant to prove that a vendor is secure; it is meant to surface exposure early enough that it can be addressed before it becomes an incident you inherit.

This distinction matters operationally because vendor systems often sit directly inside critical workflows. Order ingestion, label generation, inventory synchronization, customer service tooling, and analytics platforms create dependency chains, and a test that does not reflect those chains does little to reduce real risk regardless of how thorough it appears.

When vendors understand that testing informs access decisions, integration scope, and escalation readiness, the conversation shifts away from reassurance toward evidence, which immediately reduces noise.

Define Which Vendors Are In Scope, and Why

Not every vendor warrants the same level of scrutiny, and pretending otherwise usually produces requirements that are either ignored or gamed. Penetration testing requirements should be risk-based and explicit about who is in scope.

Start by categorizing vendors according to access and impact rather than reputation or size. Vendors that store or process customer PII, payment data, or live order information belong in the highest tier. Vendors that provide infrastructure, authentication, or integration middleware also require deeper scrutiny, because compromise there propagates quickly across systems.

Tie these categories to concrete access paths. Does the vendor maintain API access to production systems. Do they receive flat files containing live order data. Do their tools authenticate against your identity provider. These questions matter more than vendor marketing claims because they describe how failure would actually travel.

Document exclusions clearly. If certain vendors are out of scope, state why and define what would change that status. This prevents scope drift during audits and avoids last-minute exceptions when integrations quietly expand exposure.

Grounding scope decisions in access and operational impact gives both internal teams and vendors a shared frame of reference, which reduces argument later.

Specify What "Penetration Testing" Means in This Context

Asking for "a penetration test" without definition almost guarantees disappointment. Vendors interpret the phrase generously, often providing the least invasive assessment that still qualifies by name.

Requirements should define penetration testing in functional terms. Specify whether testing must include external, internal, authenticated, or application-layer coverage, and tie those expectations to the vendor's role in your environment. A vendor that exposes APIs handling order data should be tested at the application and integration layers, not just at the network edge.

Clarify expectations around realism. Automated scanning alone is not penetration testing. Manual testing that attempts to chain vulnerabilities, abuse business logic, or bypass controls is where useful insight comes from, especially for systems embedded in fulfillment workflows.

Define which environments are acceptable. Production testing may not always be possible, but testing that excludes production-equivalent configurations often misses the issues that matter most. If staging environments are used, require confirmation that configurations, access controls, and data flows mirror production in all material ways.

These definitions protect you from polished reports that answer questions you did not actually ask.

Set Testing Frequency Based on Change, Not Habit

Annual testing has become a default expectation, but frequency should follow risk and change rather than tradition. Vendor penetration testing requirements should reflect how often meaningful exposure shifts.

Define a baseline cadence for in-scope vendors, typically annual for high-risk relationships, then define triggers that override the calendar. Major releases, architectural changes, expanded data access, or emergency fixes should prompt additional testing regardless of schedule.

Tie these triggers to vendor obligations. Vendors should be required to notify you when changes occur that materially affect security posture. Testing loses value if it runs on a clock while systems evolve underneath it.

Acknowledge operational constraints. Penetration testing can be disruptive, especially when authenticated or integration-level testing is involved. Allow coordinated scheduling without weakening expectations; cooperation improves when constraints are explicit rather than assumed.

The goal is not more testing, but testing that remains aligned with actual exposure.

Define Who Performs the Test, and Under What Constraints

Who performs the test matters as much as what is tested. Requirements should state whether vendor self-testing is acceptable, when independent third-party testing is required, and what qualifications testers must meet.

For high-risk vendors, independent testing is often necessary to reduce bias and increase credibility. State expectations clearly, including tester qualifications, experience, and independence. Avoid vague language that invites interpretation.

If vendor-conducted testing is permitted, require transparency. Vendors should disclose who performed the test, what methodology was used, and what limitations applied, so results can be evaluated properly.

Also define rules of engagement. Testing should be authorized, time-bound, and coordinated to avoid unintended operational impact. Clear constraints protect both parties and prevent testing from becoming an incident in its own right.

Specify Deliverables That Enable Decisions

Accepting "a report" without definition invites inconsistency. Penetration testing requirements should specify what must be delivered and what is not sufficient.

Require an executive summary that explains what was tested, what was found, and what matters most, written so operations and IT can act on it. Technical detail should support decision-making, not obscure it.

Findings should describe exploitability and business impact, not just vulnerability names. An issue that enables order manipulation or data exfiltration carries different weight than one affecting a non-critical feature, even if technical severity appears similar.

Be explicit about exclusions. Raw scan output, marketing summaries, or reports without remediation context should not satisfy the requirement. Stating this upfront saves time and avoids corrective cycles later.

Define Expectations for Remediation and Follow-Up

A penetration test without remediation expectations is a snapshot, not a control. Requirements should define what happens after results are delivered.

Specify timelines for addressing critical and high-risk findings, along with expectations for communication during remediation. Vendors should explain what was fixed, what was mitigated, and what remains open, with reasoning.

Allow staged remediation when immediate fixes would create operational risk, but require interim controls and documented acceptance. This mirrors how internal teams manage tradeoffs and creates consistency across boundaries.

Define when retesting is required. Significant findings should be validated after remediation, either through targeted retesting or agreed alternatives, so issues do not linger unresolved.

Integrate Testing Into Vendor Risk Management

Penetration testing requirements should feed into onboarding, renewal, and escalation processes rather than living in isolation.

During onboarding, results inform initial access levels and integration scope. During renewals, trends in findings and remediation behavior matter as much as individual issues; vendors who respond clearly and quickly reduce uncertainty, while those who delay increase it.

Testing should also inform incident response planning. Understanding how a vendor's systems fail under pressure helps determine escalation paths and early warning signals before incidents spread.

When testing is integrated this way, reports become leverage for better behavior rather than static compliance artifacts.

Document Exceptions, Evidence, and Rationale

No requirement set is absolute. Penetration testing requirements should include a controlled path for exceptions without eroding credibility.

Define who can approve exceptions, for how long, and under what conditions. Temporary exceptions should include review dates so accepted risk does not become invisible risk.

Be explicit about evidence retention. Reports, remediation attestations, and approvals should be stored in a way that supports audits and internal review without unnecessary overhead.

Most importantly, require rationale. Months later, when context has faded, decisions should still be explainable. Documentation preserves intent, not just outcome.

Review and Adjust as the Vendor Ecosystem Changes

Vendor ecosystems evolve continuously, and penetration testing requirements must evolve with them. Static requirements eventually misrepresent reality.

Set review triggers tied to meaningful change rather than the calendar. New data types, new integration patterns, regulatory shifts, or repeated findings across vendors should prompt reassessment.

Assign ownership for maintaining the requirements and require updates when assumptions no longer hold. This keeps the program aligned with operational reality rather than audit memory.

When done well, penetration testing requirements reduce surprise, clarify expectations, and make vendor risk visible early enough to manage deliberately rather than under duress.

FAQ

Do all vendors need penetration testing?
No. Requirements should be risk-based, tied to access and operational impact.

Is annual testing sufficient?
Only if systems and access remain stable. Meaningful change should trigger additional testing.

Can vendors test themselves?
Sometimes. Higher-risk vendors typically require independent third-party testing.

How is this different from vulnerability scanning?
Scanning finds known issues at scale; penetration testing explores how issues can be chained and exploited in real conditions.

Where does a 3PL like G10 fit?
By absorbing operational complexity and enforcing disciplined systems, which limits how vendor risk propagates into daily fulfillment and restores confidence when tradeoffs must be made.