Vendor due diligence that doesn't stop at onboarding.
Vendor due diligence is how you verify that a supplier's technology, security and practices won't become your risk. Most organisations check once at onboarding and never look again, while the vendor's stack, staff and subprocessors keep changing. StackUp puts vendor due diligence on a standard, repeatable framework, with automation to keep it running.
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Exposure across key vendors
$270,000
- HighCritical vendor, no breach notification clause$85K
- HighPayment data with an unassessed supplier$75K
- MediumNo exit plan for core platform vendor$65K
- Quick winRe-assess top five vendors on one framework$45K
Trusted by former CTOs of
The gap
Why vendor due diligence fails after the contract is signed
The onboarding questionnaire captures a vendor at their best moment. Every quarter after that, the answers age, and the risk quietly transfers to you.
One framework for every vendor
Ad-hoc reviews produce incomparable answers: one vendor judged on a spreadsheet, another on a phone call. StackUp scores vendor management as one of the eight pillars of your technology function, so third-party risk is assessed on the same evidence-based standard as everything else, and expressed in dollars.
Oversight that keeps running
Vendors change, ownership, subprocessors, security posture. On StackUp's Continuously Improve plan, vendor due diligence is automated, so re-assessment happens on cadence rather than after an incident. Where a vendor's security is the concern, go deeper with cybersecurity due diligence; where you are absorbing their systems in a deal, run IT due diligence.
How it works
Three steps to standing vendor oversight
Baseline
Put every key vendor on one standard.
- Assess your vendor management posture across the stack
- Identify unassessed suppliers handling sensitive data
- Under an hour to establish the baseline
Prioritise
See which vendor risks are worth money.
- Each exposure sized in dollars, not severity colours
- Contract gaps flagged: notification, exit, data ownership
- Board-ready view of third-party risk
Monitor
Keep diligence current as vendors change.
- Automated vendor due diligence on the platform
- Re-assessment on cadence, not after incidents
- Track risk trend across your vendor portfolio
Why StackUp
Beyond the onboarding questionnaire
Questionnaires document intentions. A standing framework measures reality, and keeps measuring it.
Questionnaire-based vendor reviews
- A 200-question spreadsheet nobody re-reads
- Point-in-time answers, stale within a quarter
- A different bar for every vendor
- No link between vendor risk and dollars
StackUp
- One standard framework across every vendor
- Re-assessment as vendors and usage change
- Exposure expressed in dollars and priorities
- Automated vendor due diligence built into the platform
Reviews
What leaders say about standardised oversight
Executives on moving third-party and technology risk onto one measurable standard.
Not only saved us significant effort and costs but also ensured we had the insights needed to confidently move forward in our deal process.
Takes the subjectivity and emotion out of assessing technology capability and drives focus on the right areas for improvement.
Comprehensive and fast.
Proof
Oversight that was ready before the question
Real engagements where standing, evidence-based oversight replaced point-in-time checks.
Board secures independent technology oversight before it becomes urgent
This board wanted documented, ongoing evidence that technology and third-party risk was controlled, StackUp delivered the structured overview within 48 hours and the cadence to keep it current.
"This gave us evidence without turning it into a six-month audit exercise."
Investor accelerates technology due diligence without cutting corners
A PE investor applied the same standard framework across a deal target's technology and vendor estate, turning three weeks of discovery into 48 hours.
"We didn't want to replace our advisors. We just didn't want to spend three weeks figuring out what existed before we could talk about what actually mattered."
FAQs
Vendor Due Diligence questions, answered
What is vendor due diligence?
Vendor due diligence is the structured evaluation of a third-party supplier's technology, security, financial stability and practices before, and during, a commercial relationship. For technology vendors it covers data handling, security posture, resilience, subprocessors and contract terms such as breach notification and exit provisions.
What should vendor due diligence assess?
Five areas do most of the work: data security and privacy (what the vendor can access and how it's protected), operational resilience (backup, recovery, continuity), contractual protections (notification, audit rights, exit and data return), concentration risk (how hard the vendor is to replace) and compliance posture. Each should carry an owner and a review date.
How often should vendors be re-assessed?
Critical vendors quarterly or on any material change, new ownership, new subprocessors, a security incident, a big usage expansion. Lower-tier vendors annually. The honest answer is: more often than almost any organisation currently manages, which is why StackUp automates vendor due diligence rather than relying on calendar discipline.
How is this different from a security questionnaire?
A questionnaire records what the vendor says about themselves at one moment. A due diligence framework scores the risk the relationship actually creates for you, on evidence, on a consistent standard, with a dollar figure, and repeats the check as things change. The questionnaire is an input; it was never the oversight.
How does StackUp automate vendor due diligence?
Vendor management is one of the eight pillars in every StackUp assessment, and the Continuously Improve plan includes automated vendor due diligence, standing re-assessment with AI agent insights, tracked actions and a portfolio view. You set the standard once and the platform keeps applying it.
Put every vendor on one standard
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