KNOWVENDOR
VENDOR RISKPRICINGABOUT
Sign inStart free
© 2026 KnowVendor
Vendor RiskPricingAboutContactTermsPrivacy

KnowVendor provides informational data from public sources only. Not legal advice.

Federal procurement

Federal contractor due diligence using verified public-source data

Before onboarding a federal contractor or subcontractor, procurement and compliance teams need to verify SAM registration, check exclusion status, confirm identifiers, and screen for carrier compliance. This page covers the full process.

Search a contractorCheck SAM exclusion status

What is federal contractor due diligence?

Federal contractor due diligence is the process of verifying a vendor's eligibility and compliance status before awarding a federal contract or subcontract. It differs from general vendor screening because federal rules create specific legal obligations on prime contractors: under FAR 52.209-6, primes must confirm that all subcontractors are not on the SAM excluded parties list before award.

Beyond legal requirements, due diligence protects your organization from performance risk, reputational exposure, and potential audit findings. A contractor with a prior exclusion history, an active out-of-service order, or lapsed SAM registration may present risks that are not visible from a name search alone.

The six-step verification process

01

Confirm SAM.gov registration

Any vendor seeking a federal contract must be registered in the System for Award Management. Confirm that the vendor holds a current UEI and that their SAM registration is active. An inactive registration is a procurement disqualifier before any risk check is needed.

02

Check the SAM exclusion list

Search the Excluded Parties List System using the vendor's UEI. An excluded vendor cannot receive federal contracts, subcontracts, or assistance awards. Under FAR 52.209-6, prime contractors must verify subcontractors are not excluded before award.

03

Verify the UEI and CAGE code

The Unique Entity Identifier (UEI) is the primary federal vendor identifier since April 2022. The CAGE code is a NATO/DoD identifier that often appears alongside UEI on exclusion records. Confirm both match the legal entity you are onboarding.

04

Check FMCSA compliance for transportation vendors

If the vendor operates motor carriers, confirm their FMCSA compliance status using their USDOT number. An active out-of-service order means the carrier cannot legally operate. This check is required for any logistics or transportation subcontracting.

05

Review federal contracting activity

USAspending.gov shows a vendor's award history across federal agencies. This is not a risk signal — a vendor with awards is not inherently safe and a vendor without them is not inherently risky — but it provides context on procurement experience and agency relationships.

06

Document the checks

Keep a timestamped record of every check performed, what was found, and how records were linked to the legal entity. Use a consistent methodology across all vendor onboardings so your procurement process is auditable.

Why identifiers matter more than names

Name-based exclusion searches produce false positives. “National Construction LLC” or “American Services Inc” may appear hundreds of times across different states and legal structures. An exclusion record for one entity with a similar name is not an exclusion for your vendor.

Deterministic due diligence uses the vendor's UEI or CAGE code to resolve identity before linking any risk record. KnowVendor only confirms an exclusion link when a verified identifier match exists at confidence 0.99 or above. A name-only candidate match is flagged as unresolved, not surfaced as confirmed risk.

UEI

Unique Entity Identifier

Primary federal vendor identifier since 2022. Issued by SAM.gov. Required for all federal contracts.

CAGE

Commercial and Government Entity Code

NATO/DoD identifier. Used alongside UEI. Often the only identifier on older exclusion records.

USDOT

US DOT Number

FMCSA identifier for motor carriers. Required for any transportation or logistics compliance check.

SAM exclusion check in federal due diligence

The SAM.gov exclusion list is the single most important check in federal contractor due diligence. An excluded vendor is legally barred from receiving any federal award. The exclusion applies across all agencies and all programs for the duration of the exclusion period.

Exclusions are issued for: prior contract fraud, bribery, willful failure to perform, tax delinquency, suspension pending investigation, and other causes. Some exclusions are permanent; others expire after a defined period. An exclusion that has expired is still visible in the historical record and should be noted in your documentation.

Important limitation

The SAM exclusion list is historical. Many excluded entities have not re-registered with SAM after exclusion and do not have a current UEI. KnowVendor's identifier-based match rate for exclusion records is approximately 1%. This is expected and correct: not all excluded parties can be confirmed against a legal entity. A no-match result does not mean the vendor is clear — it may mean the record predates UEI registration.

How to search the SAM exclusion database

How KnowVendor supports contractor due diligence

KnowVendor searches SAM.gov registration, exclusion records, FMCSA carrier data, and federal contracting activity in a single lookup. Search by UEI, CAGE code, USDOT number, or company name. Paid reports include the full risk event detail, source evidence, match confidence score, and a printable record for procurement documentation.

Free search includes

  • Legal entity name and identifier type
  • State of registration
  • Number of sources checked
  • Presence of risk events (yes/no)
  • SAM exclusion flag when confirmed by UEI

Full report ($19) or Pro

  • Full exclusion detail with exclusion type and cause
  • SAM registration history
  • Federal contracting activity summary
  • FMCSA out-of-service history (when available)
  • Match confidence score and methodology
  • Printable report for procurement records
Search a contractorCompare plans

Related guides

How to Check if a Vendor Is SAM Excluded

Step-by-step guide to the SAM exclusion lookup process and what exclusion categories mean.

How to Verify a Federal Contractor Before Onboarding

Full federal contractor verification workflow covering SAM, FMCSA, and source coverage.

UEI Numbers Explained

How to find and use a UEI for federal vendor verification and exclusion checks.

Vendor Due Diligence Checklist

A complete checklist for procurement teams covering all major public-source risk signals.

The information on this page is for general informational purposes only and does not constitute legal advice. Federal procurement rules and FAR requirements should be reviewed with qualified legal counsel. KnowVendor reports are not a substitute for your organization's compliance process.