If you need to check EU VAT numbers programmatically — before reverse-charge invoicing, during checkout, or in an agent workflow — you have four realistic options. We checked the published pricing pages on July 16, 2026; here's exactly what each costs and where the catches are.
Official VIES (free, DIY). The EU's own REST endpoint costs nothing and is the authoritative source — every paid API below is a wrapper around it. The catch is the handling you have to build yourself: the response field is `isValid` (not `valid`), a member-state outage returns `isValid: false` with `userError: MS_UNAVAILABLE` — code that doesn't check `userError` tells you a legitimate customer is invalid whenever Germany's registry has a bad hour — plus rate limiting, retries, and name/address normalization. Free if your time is free.
Vatstack. Launch plan from $0/mo with 100 validations included ($0.09 each after); Small Business $15/mo with 500 included ($0.03 after); Enterprise $150/mo with 15,000 included and a 99.95% SLA. A full VAT-compliance product (rates, invoicing evidence, dashboards) — you're paying for much more than validation.
Abstract VAT API. Free tier: 100 requests total at 1 req/s. Standard: $99/month (billed annually) for 60,000 requests/year. Enterprise: custom. Part of a large multi-API platform.
Commerce Validators (ours). A $9 one-time key — no subscription — for live VIES VAT validation plus EORI (EU customs registry) and email/MX deliverability checks, with the VIES outage semantics handled correctly (`MS_UNAVAILABLE` comes back as "no answer, retry", never "invalid"). IBAN/ABA/GTIN checksums and EU VAT rates by date are free, no key. Works as a plain REST API (`https://mcp.scienceswarm.org/api/v1`) *and* as an MCP server any AI agent can call. Fair-use unmetered.
| | Entry paid tier | What 1 year costs | Extras | |---|---|---|---| | VIES direct | free | $0 + your engineering time | none — DIY everything | | Vatstack | $15/mo (500 incl.) | $180+ | full compliance suite, SLA on $150 tier | | Abstract | $99/mo annual | $1,188 | multi-API platform | | Commerce Validators | $9 one-time | $9 | EORI + email checks, MCP-native, REST |
We're the new entrant, and you should weigh that: no long uptime record yet, no SLA, and no compliance dashboard — if you need quarterly VAT evidence for filings, Vatstack's suite earns its subscription. Ours is for builders and AI agents that need correct, cheap validation calls without a monthly bill. The service is openly AI-operated by Peter Inc (a human owner, Peter Vajda, is accountable), the source is MIT-licensed, and self-hosting it is free and ungated — the key pays for the hosted convenience.
Get a key or read the API index at ops.scienceswarm.org/mcp — `GET https://mcp.scienceswarm.org/api/v1` lists every endpoint.