International Companies: How to Verify US Entities via API

When a foreign company wants to open a US bank account, onboard a domestic supplier, or enter a cross-border partnership, one question dominates the due-diligence checklist: is this American business actually legitimate? For compliance teams, legal departments, and fintech platforms operating across borders, the ability to international business verify US entity records in real time is no longer a nice-to-have — it is a regulatory obligation embedded in federal law.

This article explains why US entity verification matters, which regulations demand it, and how your platform can automate the entire process using the OpenSOSData API — covering all 50 states, Washington D.C., Puerto Rico, and the U.S. Virgin Islands.

Why Verifying US Business Entities Is Critical for International Operations

Global companies engaging with US counterparties face a layered web of compliance requirements. A business registered in Delaware, Wyoming, or Florida exists as a legal fiction created by state government. Its legitimacy, good standing, and structural details live inside Secretary of State (SOS) databases — not on a company's website or a third-party data broker. Unless you query those primary sources, you are working with unverified information.

The consequences of skipping verification are severe. Under the Bank Secrecy Act (BSA), financial institutions must implement Customer Due Diligence (CDD) programs that include verifying the identity of legal entity customers. Violations carry civil penalties up to $25,000 per day and criminal liability. The FinCEN Beneficial Ownership Information (BOI) rules, effective January 2024, impose additional obligations: most US companies must now report beneficial owners, and counterparties verifying those entities need accurate formation records to cross-reference ownership filings.

OFAC sanctions screening adds another layer. Before any business relationship begins, US and international parties alike must confirm that an entity is not on the Specially Designated Nationals (SDN) list — and that starts with confirming the entity exists and is in good standing.

The Regulatory Framework: BSA, KYB, and FinCEN BOI Rules

Know Your Business (KYB) Requirements

KYB is the business-entity equivalent of Know Your Customer (KYC). FinCEN's CDD Rule (31 CFR § 1010.230) requires covered financial institutions to identify and verify the identity of the beneficial owners of legal entity customers. This means collecting the entity's legal name, address, type, and formation date — all fields returned directly by the OpenSOSData API.

FinCEN BOI Reporting Under the Corporate Transparency Act

The Corporate Transparency Act (CTA) became effective January 1, 2024. Most domestic and foreign companies registered to do business in the US must file Beneficial Ownership Information reports with FinCEN. For compliance professionals verifying counterparties, this creates a parallel workflow: confirm that the entity exists at the state level, then cross-reference BOI filings. Secretary of State data is the foundation of that first step.

BSA Anti-Money Laundering (AML) Programs

BSA-regulated institutions must maintain written AML programs that include entity verification as a core control. Automated, auditable lookups via API — with timestamped responses from official state records — provide the defensible documentation examiners expect during audits.

What Information Does US Entity Verification Return?

A single API call to OpenSOSData returns the following fields directly from official Secretary of State databases:

• Entity Name — the legally registered business name
• Entity Type — LLC, Corporation, LP, LLP, etc.
• Entity ID — the unique state-assigned registration number
• Status — Active, Dissolved, Revoked, Suspended, or similar
• Formation Date — when the entity was officially registered
• Registered Agent Name and Address — the statutory agent for service of process

These data points satisfy the primary documentary requirements of KYB workflows and provide the baseline for downstream OFAC screening and BOI cross-referencing.

Coverage: All 50 States + Territories

Unlike fragmented solutions that cover only popular incorporation states, OpenSOSData provides unified access to 34 million+ entities across all 50 US states, Washington D.C., Puerto Rico, and the U.S. Virgin Islands — through a single API endpoint. That matters when a counterparty is incorporated in a less common jurisdiction like South Dakota or Hawaii and your existing vendor returns no data.

Pricing That Scales With Your Workflow

Pricing is pay-as-you-go with no subscription commitment. For large-scale international onboarding programs running thousands of lookups per day, the volume tiers make automated entity verification extremely cost-effective. Create a free account to get started immediately.

Practical Code Example: Verifying a US Entity via API

The OpenSOSData API uses a single endpoint: POST https://api.opensosdata.com/v1/lookup. The cache_preference parameter controls whether you receive a real-time Secretary of State query (live_only), a cached result (cache_only), or a cost-optimized hybrid (cache_first).

Python Example

import requests

# Replace with your actual OpenSOSData API key
API_KEY = "your_api_key_here"
ENDPOINT = "https://api.opensosdata.com/v1/lookup"

# Build the request payload
# Use cache_preference: "live_only" for real-time KYB verification
# Use "cache_first" for high-volume, cost-optimized workflows
payload = {
    "entity_name": "Acme Holdings LLC",
    "state": "DE",                      # Two-letter state code (Delaware)
    "cache_preference": "live_only"     # Forces a direct Secretary of State query
}

headers = {
    "x-api-key": API_KEY,
    "Content-Type": "application/json"
}

response = requests.post(ENDPOINT, json=payload, headers=headers)

if response.status_code == 200:
    data = response.json()

    # Extract key KYB fields for compliance documentation
    print("Entity Name:       ", data.get("entity_name"))
    print("Entity Type:       ", data.get("entity_type"))
    print("Entity ID:         ", data.get("entity_id"))
    print("Status:            ", data.get("status"))
    print("Formation Date:    ", data.get("formation_date"))
    print("Registered Agent:  ", data.get("registered_agent_name"))
    print("Agent Address:     ", data.get("registered_agent_address"))
else:
    print(f"Lookup failed: {response.status_code} - {response.text}")

cURL Example

# Live entity lookup for a California corporation
# cache_preference=live_only ensures data comes directly from the SOS database
curl -X POST https://api.opensosdata.com/v1/lookup \
  -H "x-api-key: your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "entity_name": "Pacific Ventures Corp",
    "state": "CA",
    "cache_preference": "live_only"
  }'

Full parameter documentation, response schemas, and error codes are available in the official API documentation.

Recommended Verification Workflow for International Due Diligence

Integrating OpenSOSData into a cross-border KYB program typically follows this sequence:

1. Collect entity details from the counterparty — business name and state of formation at minimum.
2. Run a live SOS lookup using cache_preference: live_only to confirm existence and good standing.
3. Store the timestamped API response in your compliance record system for audit trail purposes.
4. Cross-reference the registered agent address against known high-risk registered agent farms (common in Wyoming and Nevada shell company structures).
5. Screen the entity name and beneficial owners against OFAC SDN lists and adverse media databases.
6. Compare formation date against FinCEN BOI filing deadlines — entities formed after January 1, 2024, had 90 days to file; those formed earlier had until January 1, 2025.
7. Flag discrepancies — a dissolved or revoked entity status is an immediate red flag requiring escalation before any transaction proceeds.

Why Automated API Lookups Beat Manual Research

Manually searching individual Secretary of State websites is time-consuming, inconsistent, and unauditable. Each state has its own search interface, data formatting conventions, and update cadence. A compliance analyst manually verifying 50 entities per day across multiple states introduces human error and creates documentation gaps that regulators find unacceptable.

An API-first approach solves all three problems: speed (lookups complete in seconds), consistency (identical data structure regardless of state), and auditability (every response is logged with a timestamp and query parameters). For international companies building US-market compliance infrastructure, this is not optional — it is the baseline standard expected by US banking partners and regulators.

Frequently Asked Questions

Conclusion

For international companies engaging with US business counterparties — and for US professionals managing cross-border relationships — real-time entity verification is a compliance cornerstone. BSA obligations, FinCEN's BOI rules, and standard KYB best practices all converge on the same requirement: you must confirm that the entity you are dealing with actually exists, is in good standing, and matches the information your counterparty has provided.

The OpenSOSData API provides the fastest, most cost-effective path to that verification, pulling live data from official Secretary of State sources across all US jurisdictions through a single, developer-friendly endpoint. Whether you are processing ten onboardings per month or tens of thousands per day, the pay-as-you-go model scales with your needs without locking you into expensive subscriptions.

Start your free account today and integrate authoritative US entity verification into your compliance workflow in minutes.