Vendor concentration risk is the exposure a company takes on when too much of a critical function — spend, data processing, infrastructure, a specific capability — depends on too few vendors. It is a familiar concept in portfolio finance (don’t put all your capital in one position) applied to the supply chain: if one vendor relationship goes wrong, how much of the business goes wrong with it?
Why Spend Share Alone Isn’t Enough
The most common starting point is spend concentration — the share of total vendor spend going to the top few suppliers, often flagged when a single vendor crosses a threshold like 25% of total spend in that category. That’s a useful first pass, but spend doesn’t capture criticality on its own. A relatively low-spend vendor supplying a single-sourced component, a specialized regulatory filing, or a piece of infrastructure with no readily available substitute can carry more real concentration risk than a much larger contract for a commodity service with a dozen viable alternatives.
What to Actually Measure
- Spend concentration — the share of total spend, by category, held by each vendor; useful as a first screen, not a final answer.
- Criticality — whether the vendor supports a mission-critical process, proprietary technology, or a customer-facing service that would be difficult or slow to replace.
- Substitutability — how many viable alternative vendors exist, and how long a real transition would realistically take if the relationship ended tomorrow.
- Shared dependencies — whether multiple "different" vendors actually share an underlying dependency (the same cloud region, the same identity provider, the same subcontractor), which hides concentration risk inside apparent diversification.
- Contractual exposure — the total value and obligation load across every active agreement with that vendor, not just the primary contract someone remembers signing.
Why This Is a CLM and TPRM Problem, Not Just a TPRM Problem
The last item on that list is where concentration risk assessments most often fall short in practice: answering "what is our total exposure to this vendor across every active agreement" requires contract data — value, term, obligations — and vendor risk data in the same place. When contract and vendor risk data live in separate systems, that question turns into a manual cross-referencing exercise, usually only attempted after a board asks it directly rather than as a standing, continuously-answerable metric.
This is one of the reasons vendor risk scoring models that include a dedicated concentration dimension — rather than folding it into a general "financial risk" score — tend to surface it earlier: it forces the question to be asked on every vendor, not just the ones that happen to trigger a spend-threshold alert.