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DK VAT Number Checksum Validator
x402
DK VAT Number Checksum Validator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-02).
Validates whether a Danish VAT (CVR) number passes the DK checksum algorithm, without performing a live registry lookup.
Price / call$0.003
Success—
StatusUnknown
How this service works
Call when an agent needs whether a DK VAT checksum is valid. No registry lookup. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/check-vat-dk first.
Output
Returns a boolean or structured result indicating whether the provided Danish VAT (CVR) number passes the DK modulus-11 checksum algorithm. No live registry or government database is queried — this is a purely computational, offline validation.
Example use cases
E-commerce checkout VAT validation
“Before we process this Danish business customer's order, can you verify that their VAT number 29876543 passes the DK checksum? We just need to know if it's structurally valid, not a full registry check.”
B2B invoice data quality check
“I have a list of Danish supplier VAT numbers I need to clean up — can you check if 55133018 is a valid DK VAT number by checksum so I can flag bad entries before importing them?”
Onboarding form real-time validation
“A new Danish business partner entered 87654321 as their CVR number during signup — can you run the DK VAT checksum on it to tell me if the format is mathematically valid?”
Technical details
Endpoint
POSThttps://agentshelf.syntexa.ch/v1/check-vat-dk?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a fast, low-cost, offline checksum validation of a Danish VAT/CVR number and do not need to confirm the number is actively registered in the Danish business registry. Ideal for form validation, data cleaning, and pre-filtering before more expensive registry lookups. Use the free sandbox endpoint (/v1/sandbox/check-vat-dk) first if available.
Side effects
- Empty or missing value field returns an error
- Value exceeding 20000 characters rejected
- Malformed JSON body returns 400
- Non-numeric or incorrectly formatted VAT strings may return invalid rather than an error
- x402 payment not provided or insufficient results in 402 Payment Required
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| data | — | JSON value for schema-check SKUs. Omit it on string checks such as email or IBAN. |
| value | string | Value to check. The route description names the format: email, phone, IBAN, postal code, VAT, national id, or similar. |
| schema | — | JSON Schema document for schema-check SKUs. Omit it on string checks. |
Tags
x402
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