{"uid":"cap_dL0tmcNeyi5hvh_0-xmxO","slug":"gb-vat-number-checksum-validator-a27d987c","name":"GB VAT Number Checksum Validator","description":"Call when an agent needs whether a GB VAT checksum is valid. No registry lookup. Exact $0.006 USDC. Prefer unpaid POST /v1/sandbox/check-vat-gb first.","url":"https://agentshelf.syntexa.ch/v1/check-vat-gb?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"data":{"description":"JSON value for schema-check SKUs. Omit it on string checks such as email or IBAN."},"value":{"type":"string","examples":["100000089"],"maxLength":20000,"minLength":1,"description":"Value to check. The route description names the format: email, phone, IBAN, postal code, VAT, national id, or similar."},"schema":{"description":"JSON Schema document for schema-check SKUs. Omit it on string checks."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.006","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":"$0.006/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.006","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.006","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Qac_v2xU44ah4o97X4cLT","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.006","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Validates whether a UK (GB) VAT number has a correct checksum, using local computation only — no HMRC registry lookup.","exampleAgentPrompt":"Can you check if this UK VAT number has a valid checksum: GB 123456789? I just need to know if it's structurally correct, not a live HMRC lookup.","exampleUseCases":[{"title":"E-commerce checkout VAT validation","prompt":"Before I save this supplier's details, can you verify whether the VAT number GB 333289454 has a valid checksum? I don't need an HMRC registry check, just want to make sure the number is structurally correct."},{"title":"Bulk invoice data cleaning","prompt":"I have a UK VAT number from a vendor invoice — GB 107328000 — can you run a checksum validation on it to see if it's well-formed before I submit the invoice to accounting?"},{"title":"Onboarding form validation","prompt":"A new business just filled in their VAT number as GB 654321987 during registration — can you quickly validate whether that checksum is correct so we know if they made a typo?"}],"resultDescription":"Returns a boolean or structured result indicating whether the supplied GB VAT number passes the standard modulus-97 (or GB-specific) checksum algorithm. No live registry or HMRC lookup is performed — purely a local, deterministic checksum computation.","failureModes":["Input string is empty or missing — returns error or invalid result","Input contains non-numeric or unexpected characters that cannot be parsed as a GB VAT number","VAT number is for a non-GB jurisdiction — result may be unreliable or incorrect","Network or service error resulting in a non-200 response"],"whenToPreferThis":"Choose this endpoint when you need fast, cheap, offline checksum validation of a GB VAT number without any live HMRC registry call. It is ideal for form validation, data cleaning, or pre-screening before a more expensive registry lookup. Prefer the free sandbox endpoint (/v1/sandbox/check-vat-gb) for testing. Do not use this if you need to confirm the VAT number is actually registered and active with HMRC.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T06:50:11.113Z","isFirstParty":false,"canonicalSlug":"gb-vat-number-checksum-validator-a27d987c"}