• VALID
  • INVALID
  • MALFORMED
  • REVIEW

How to validate B2B tax IDs with your AI

Connect the VAT Tax Validator once. From then on, your AI handles the heavy lifting of checking tax ID integrity.

Ask AI about this page

Short answer

How can I use my AI to check VAT numbers?

Your AI uses the validate_vat tool to confirm that a tax ID follows the correct country format and passes its mathematical checksum. This prevents you from processing invoices with typos or fake IDs. You'll see exactly which numbers are valid and which ones fail.

Validation outcomes

Where every check lands.

The AI sorts every tax ID check into one of these four buckets.

VALID

Confirmed tax IDs

The AI confirms the ID is structurally sound and mathematically correct. You can trust these for your records.

INVALID

Failed checksums

The AI flags IDs that fail the mathematical check. These are usually simple typos or incorrect digits.

MALFORMED

Format errors

The AI catches IDs that don't match the required country pattern. These are rejected immediately.

REVIEW

Human intervention

If the AI hits an edge case it can't resolve, it flags the entry for you to check manually.

The workflow

What your AI does when a tax ID arrives.

The AI acts as a gatekeeper for your invoice data.

  1. Pattern matching

    The AI looks at the string to see if it matches the specific character length and prefix for that country.

    validate_vat

  2. Checksum verification

    The AI runs the mathematical algorithm required for that specific tax jurisdiction to ensure the digits are valid.

    validate_vat

  3. Error categorization

    The AI determines if the failure is a simple typo or a complete format mismatch.

    validate_vat

  4. Status reporting

    The AI provides a clear pass or fail status for every ID it processes.

    validate_vat

Try it

Copy these to start.

Use these prompts to kick off the validation process.

Starting points

Swap the bracketed text for your actual data sources like a spreadsheet or a list of emails.

JS VAT Connector

You're all set. Choose your MCP client and follow the setup instructions.

Connector linkhttps://edge.vinkius.com/vk_preview_R2GmhYreLXbhdtOTpoumP5qeOFc4ejlazomdV4PZ/mcp

Claude Desktop

Follow the steps below to connect in seconds.

  1. 1In Claude Desktop, open Settings → Connectors.
  2. 2Click “Add custom connector” and paste the connector link above as the remote MCP server URL.
  3. 3Click Add and start a new chat — JS VAT capabilities are ready to use.
Configuration · claude_desktop_config.jsonCopy
{
  "mcpServers": {
    "vat-tax-validator-mcp": {
      "url": "https://edge.vinkius.com/vk_preview_R2GmhYreLXbhdtOTpoumP5qeOFc4ejlazomdV4PZ/mcp"
    }
  }
}
Copy into chat04

  • Check these VAT numbers from my Google Sheet for any errors.

  • Validate the tax IDs in this list of recent invoices.

  • Scan the contact list in my CRM and flag any invalid VAT numbers.

  • Run a checksum check on the tax IDs found in this text block.

  • Claude
  • ChatGPT
  • Cursor
  • VS Code
  • Windsurf
  • Claude Code
  • JetBrains
  • Cline

Start here

Connect VAT Tax Validator once, then ask.

Just click to connect. Your credentials stay encrypted, and you can immediately start asking your AI to check your data.

Connect VAT Tax Validator to your AI

FAQ

How the task behaves

  • 01

    Does the AI check if the business is actually registered?

    No. The AI only checks if the number is mathematically valid and follows the correct format. It does not check live government databases for active registration.

  • 02

    Can the AI fix a typo in a tax ID automatically?

    No. The AI identifies that a number is invalid, but it won't guess what the correct number should be. You have to fix the data yourself.

  • 03

    Can I use this to validate US Sales Tax IDs?

    No. This specific tool is built for VAT numbers.

  • 04

    Will the AI delete my original invoice files?

    No. The AI only reads the data you provide to perform the validation.

  • 05

    What happens if a VAT number is valid but the company is defunct?

    The AI will mark the number as valid because it passes the mathematical checksum. It cannot verify the real-time legal status of a company.

  • More questions about VAT Tax Validator? The Connector page answers them. See everything the VAT Tax Validator Connector can do

Connect JS VAT to Claude, Cursor, ChatGPT & more