{"uid":"cap_LAtHSFzUZyFsYx7IXfElv","slug":"us-ein-format-and-prefix-validator-8da2dcf9","name":"US EIN Format and Prefix Validator","description":"Check a US EIN's format and whether its 2-digit prefix is one the IRS assigns. Format only, not existence.","url":"https://bank-validators.x402tookit.com/ein-format?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["ein"],"properties":{"ein":{"type":"string","description":"US employer identification number, NN-NNNNNNN, e.g. 12-3456789"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asOf":{"type":["null","string"]},"prefix":{"type":["null","string"]},"source":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"formatted":{"type":["null","string"]},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"issuingCampuses":{"type":["array","null"],"items":{"type":"string"}}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_oA1rxVwgAUVLg8lEFFaRg","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates a US Employer Identification Number (EIN) by checking its format and whether its 2-digit prefix is a valid IRS-assigned prefix — format only, not real-time IRS existence lookup.","exampleAgentPrompt":"Can you check whether the EIN 12-3456789 is properly formatted and has a valid IRS-assigned prefix?","exampleUseCases":[{"title":"Vendor onboarding tax ID check","prompt":"We're onboarding a new vendor and they gave us EIN 27-1234567 — can you verify the format is correct and the prefix is one the IRS actually assigns?"},{"title":"Payroll system data validation","prompt":"Before we submit payroll, can you confirm that the employer EIN 83-9876543 has the right format and a legitimate IRS prefix?"},{"title":"Automated W-9 form review","prompt":"A contractor submitted a W-9 with EIN 00-1234567 — check whether that's a valid EIN format and if the prefix 00 is IRS-assigned."}],"resultDescription":"Returns a verdict (valid/invalid), the formatted EIN, the 2-digit prefix, associated IRS issuing campuses, a human-readable summary, reasons for any failure, a disclaimer clarifying this is format-only (not existence), and a list of checks not performed.","failureModes":["Malformed EIN string (missing dash, wrong digit count) returns invalid verdict with reasons","Unrecognized or unassigned IRS prefix returns invalid verdict with prefix flagged","Missing required 'ein' query parameter returns an error","Non-numeric characters in EIN cause format failure","Service may return degraded=true if reference data is stale"],"whenToPreferThis":"Use this endpoint when you need fast, cheap, offline-style validation of a US EIN's format and IRS prefix assignment — ideal for pre-screening form submissions, vendor onboarding, or payroll data quality checks where real-time IRS existence lookup is unnecessary or unavailable. Prefer this over full IRS lookup when speed and cost matter and format correctness is sufficient.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-11-02T18:33:03.522Z","isFirstParty":false,"canonicalSlug":"us-ein-format-and-prefix-validator-8da2dcf9"}