Validate one EU VAT number (VIES)

Check whether an EU VAT number (with country prefix, e.g. IE6388047V, DE811193231, HU33119856) is valid in the official VIES system (GB numbers: HMRC). Returns status (valid | invalid | invalid_format | member_state_unavailable | error | not_configured), valid, registered name and address where the member state discloses them, and a consultation_number (audit proof) when requester is a valid EU VAT. If VIES is down for that member state, fallback: true answers come from an official national source (PL Biała lista, CZ ARES, FI YTJ, FR SIRENE) or the last successful VIES result with its date; fallbacks never carry a consultation number. Use for reverse-charge invoicing, customer/supplier onboarding and checkout VAT exemption. Free 20/day per IP, then x402 $0.01.