Global LEI & Corporate Tax ID Validator API
Sub-5ms ISO 17442 LEI, US EIN, Australian ABN & UK CRN Verification Engine
The Global LEI & Corporate Tax ID Validator API performs instant, deterministic verification of essential international business identifiers: ISO 17442 Legal Entity Identifiers (LEI), US Employer Identification Numbers (EIN), Australian Business Numbers (ABN) & Company Numbers (ACN), and UK Companies House Registration Numbers (CRN).
Engineered for high-throughput KYC/AML onboarding, fintech compliance, checkout billing flows, and ERP master data hygiene: prevent mistyped tax IDs, forged registration numbers, and invalid corporate entities before downstream credit checks or regulatory filings. Validation executes entirely in pure compute across 300+ Cloudflare edge locations with sub-5ms latency and 100% uptime.
The engine includes an intelligent multi-identifier auto-detector that automatically classifies input strings into their corresponding business identifier format, verifies mathematical checksums (ISO 7064 MOD 97-10, ATO MOD-89, ASIC MOD-10), and extracts rich structural metadata including issuing LOUs, IRS campus allocation zones, and UK legal entity types.
Features
- ISO 17442 Legal Entity Identifier (LEI) MOD 97-10 checksum validation with 40+ accredited LOU issuer registry
- US Employer Identification Number (EIN) IRS Campus Service Center prefix mapping & allocation validation
- Australian Business Number (ABN) ATO MOD-89 checksum verification & embedded ACN ASIC extraction
- UK Companies House Registration Number (CRN) format validation & jurisdiction / legal entity type classification
- Intelligent auto-detection endpoint (/api/v1/validate) for unified single-field onboarding forms
- Ultra-low latency (<5ms) running on Cloudflare Workers edge network
- Deterministic pure compute with zero external subrequests or government portal downtime
Endpoints
| Method | Path | Description | Example |
|---|---|---|---|
GET | /api/v1/lei/{lei} | Validate an ISO 17442 LEI and resolve issuing LOU authority | /api/v1/lei/5493006MHB84DD0ZWV18 |
GET | /api/v1/ein/{ein} | Validate a US EIN and resolve IRS campus service center | /api/v1/ein/12-3456789 |
GET | /api/v1/abn/{abn} | Validate an Australian ABN via MOD-89 and extract embedded ACN | /api/v1/abn/51824753556 |
GET | /api/v1/crn/{crn} | Validate a UK Companies House CRN and resolve jurisdiction/entity type | /api/v1/crn/SC123456 |
GET | /api/v1/validate/{identifier} | Auto-detect and validate any supported business identifier | /api/v1/validate/5493006MHB84DD0ZWV18 |
GET | /health | Service health check | /health |
FAQ
How does the LEI validation algorithm work?
LEIs strictly follow ISO 17442 and ISO 7064 MOD 97-10. Letters are converted to numeric values (A=10 to Z=35) and computed using modulo 97 arithmetic. A valid LEI always produces a remainder of 1. The API also checks the 4-character LOU prefix against the official accredited Local Operating Unit registry.
How are US EINs validated?
EIN validation checks the 9-digit format and verifies the 2-digit prefix against the official IRS Campus Prefix allocation tables (distinguishing Brookhaven, Philadelphia, Cincinnati, Kansas City, Atlanta, Austin, Ogden, and post-2001 Online Internet issuances while rejecting unassigned IRS prefix ranges).
How is the Australian ABN verified?
The Australian Business Number uses the Australian Taxation Office (ATO) MOD-89 weighted algorithm. The first digit is decremented by 1 and multiplied by 10, while digits 2-11 are multiplied by distinct prime/odd weights [1, 3, 5, 7, 9, 11, 13, 15, 17, 19]. The sum must be divisible by 89. Digits 3-11 are also cross-checked for valid ASIC Australian Company Number (ACN) MOD-10 checksums.
Does the API require external network calls to government databases?
No. All validation is executed via pure mathematical computation and frozen static lookup registries at the Cloudflare edge. This ensures sub-5ms response times, zero external point-of-failure risks, and 100% uptime.