- Category
- EU VAT Compliance
- Status
- Live
- Platforms
- Web, API
- Stack
- Next.js, React, Prisma, PostgreSQL, Auth.js, Stripe, Tailwind CSS
Viesproof is a synchronous, requester-qualified VIES checker for checkout flows. It captures the European Commission's official consultation number for every check, including failed ones, and writes it into a hash-chained, HMAC-signed receipt, so a business can later prove it consulted the register before zero-rating an intra-Community supply.
A VAT number lookup against VIES can come back valid, invalid, or unavailable — and most integrations only handle the first two, silently treating an outage as a failure. Viesproof treats UNAVAILABLE as its own outcome and always returns a decision an integration can branch on directly, rather than a raw VIES status to re-interpret.
Every requester-qualified check is issued a consultation number by VIES itself, and Viesproof writes that number into a hash-chained, HMAC-signed receipt tied to the previous entry in the organization's chain. Editing, deleting or reordering any record breaks verification and names the exact index where the chain broke — tested adversarially, not just assumed. Failed and unavailable checks are recorded too, so the archive can demonstrate diligence even during a VIES outage.
VAT number format is validated for all 27 member states plus Northern Ireland, with GB rejected and GR normalized to EL, and a status endpoint reports live per-member-state VIES availability.
- Synchronous checkout verification
- One API call returns a decision — accept zero-rated, charge VAT, or review — instead of a raw VIES status to re-derive.
- Tamper-evident receipt chain
- Every consultation is written into a hash-chained, HMAC-signed receipt; editing, deleting or reordering any record breaks verification and names the broken index.
- Per-member-state VAT syntax & status
- Validates VAT number format for all 27 member states plus Northern Ireland, and reports live per-member-state VIES availability.
- Full audit trail, free to verify
- Re-verifies an organization's entire chain at no cost, and any single check can be re-verified on read.