# Vendor Proof Index

> Vendor Proof Index is a procurement-grade reference for sourcing vendor-verification, KYB (Know Your Business), due-diligence, and sanctions-screening vendors. Understand every service category, learn exactly what to verify before you retain a provider, request sourcing help, and explore a reference to notable real vendors in the space. Procurement support, not legal, compliance, or investment advice. This site does not itself perform verification.

Procurement support and buyer education only. Not legal, compliance, or
investment advice. This site is a sourcing directory FOR vendor-verification
service providers - it does not itself verify, certify, or vouch for any
listed vendor's service quality. No fabricated credentials, statistics,
reviews, or ratings. Data as of 2026-07-14.

## What this site is
A procurement-grade reference for sourcing and vetting vendor-verification,
KYB (Know Your Business), due-diligence, and sanctions-screening providers -
the point-in-time service layer that confirms a vendor or supplier is a real,
legitimate, financially-stable business before you sign a contract. Plus a
sourced reference to 30 notable real vendors in the space.
4 guides, 22 glossary terms, 1
procurement decision frameworks.

## Process & methodology guides
- [Supplier Verification](https://vendorproofindex.com/guides/supplier-verification) - Supplier verification is the process of confirming a supplier is a real, legally registered, financially stable business before you sign a contract with it. A complete process checks business registration, ultimate beneficial ownership, financial health, and sanctions/watchlist status, not just one of these in isolation.
- [Know Your Business Verification](https://vendorproofindex.com/guides/know-your-business-kyb) - Know Your Business (KYB) verification is the process financial institutions, marketplaces, and increasingly ordinary businesses use to confirm a business customer or vendor is legitimate: verifying its legal registration, identifying its ultimate beneficial owners, and screening it against sanctions and watchlists. It is the business-entity equivalent of Know Your Customer (KYC), which verifies individuals.

## Vendor sourcing guides
- [Vendor Background Check](https://vendorproofindex.com/guides/vendor-background-check) - A vendor background check is an investigation into a specific vendor's legal standing, ownership, financial condition, and risk history, typically performed by a managed due-diligence firm using human analysts rather than a fully automated platform. It differs from routine KYB verification by going deeper on a single vendor, often for a higher-stakes or higher-risk engagement.
- [Vendor Verification](https://vendorproofindex.com/guides/vendor-verification) - Vendor verification is the practice of confirming a vendor is a real, legally registered, and accurately represented business, typically at the point of onboarding. Providers range from self-serve API/software platforms built for high-volume automated checks to managed services with human review for lower-volume or higher-risk needs.

## Compare (procurement decision frameworks)
- [Self-Serve KYB API vs. Managed Verification Service](https://vendorproofindex.com/compare/self-serve-kyb-api-vs-managed-verification-service)

## Key pages
- [Source a vendor (sourcing request)](https://vendorproofindex.com/source-a-vendor)
- [Notable vendor verification & KYB companies](https://vendorproofindex.com/vendors)
- [Glossary](https://vendorproofindex.com/glossary)
- [Quiz (which vendor do I need)](https://vendorproofindex.com/quiz)
- [Methodology](https://vendorproofindex.com/methodology)
- [Vendors JSON API](https://vendorproofindex.com/api/vendors.json)
- [Guides JSON API](https://vendorproofindex.com/api/guides.json)
- [Regulatory references JSON API](https://vendorproofindex.com/api/regulatory-refs.json)

## Contact
hello@vendorproofindex.com