VIES Uptime Monitor

Why VIES goes down

VIES is not a central database. It is a federated proxy maintained by the European Commission that forwards every validation request to the issuing member state's national tax authority and returns whatever that backend replies with. Each country runs its own infrastructure, with its own concurrency limits (often single-digit parallel requests), its own scheduled maintenance windows, and its own outage patterns. Italy and Greece have historically been the least available; Spain rate-limits aggressively under load; smaller members occasionally drop offline for hours at a time.

The standard VIES errors, including MS_UNAVAILABLE and MS_MAX_CONCURRENT_REQ, are returned without retry guidance. Callers are left to implement their own backoff, their own country-aware fallback, and their own audit trail when a validation cannot complete. For B2B billing flows that require a consultation number for reverse-charge invoicing under Council Directive 2018/1910, an upstream outage is more than an inconvenience.

How Avatcado stays up when VIES doesn't

Avatcado fronts VIES (and HMRC, Swiss BFS UID Register, Norwegian Brønnøysund, and Australian ABR) with three resilience layers:

• A regional cache that serves recent valid results within a 24-hour TTL. Every cached response carries the original VIES consultation number so the caller retains audit evidence with no behavioural difference from a live lookup.
• Country-aware retries with exponential backoff that respect the concurrency semantics of each backend. A MS_MAX_CONCURRENT_REQ from Italy is handled differently from a transport timeout from Greece.
• Structured fallback responses when a country is fully unavailable. The upstream error code is preserved so downstream systems can decide whether to block the transaction, defer it for retry, or accept and reconcile later.

The result: Avatcado's API stays responsive even when individual member-state backends fail. Validation requests continue to return predictable, machine-readable responses with full audit metadata.

What the numbers below mean

The dashboard below reports per-country uptime, average response time, and P95 latency measured from real validation traffic routed through Avatcado. A red status badge means the upstream registry is failing. Avatcado's API will still respond (with cached or fallback data) but downstream VIES-dependent flows on other vendors will not.

Use these figures as a procurement signal when comparing VAT validation vendors. Almost every API in the category sits on top of the same VIES backend, so reliability is determined by how each vendor handles upstream failure, not by who has the "best" VIES connection. The numbers here are published so you can see exactly what the upstream looks like and how a wrapper layer changes the experience.