W System / Terms of service

Terms of service

These terms apply to the W System API at api.wsystem.dev, the MCP server and the free tools on wsystem.dev (together, the "Service"), including when the Service is called by our integrations such as the W System VIES Check plugin for WordPress. The plugin software itself is licensed under the GPLv2 or later; these terms cover only the online Service.

Provider: W System Hungary Kft.. EU VAT: HU33119856. Contact: [email protected]; see also the imprint.

1. The Service

The Service checks EU VAT numbers against the European Commission VIES service and provides other lookups from public official sources. Results reflect what those sources return at the time of the request. We are not affiliated with the European Commission or any tax authority, including HMRC.

1a. UK VAT number checks

GB VAT numbers are checked with HM Revenue & Customs' "Check a UK VAT number" API. Until our production access is active, GB results are a local format and check-digit validation (or clearly marked sandbox test data) and are flagged as such. Results reflect what HMRC returns at the time of the request. W System is independent and is not affiliated with, endorsed or approved by HMRC. You must not use the Service to check UK VAT numbers for unlawful purposes or in bulk beyond what you need for your own business checks. We never ask for your HMRC credentials.

2. Free tier and paid access

• Free tier: 20 calls per day per client IP address, no account or key needed.
• Higher volume: x402 pay-per-call, Apify Actors, or a monthly plan with an API key once plans are available. Prices are shown on the pricing section and exclude VAT.
• When a quota is used up the API answers with HTTP 429 or 402 until the next day or until payment.

3. Acceptable use

Do not use the Service unlawfully, try to get around quotas (for example by rotating IP addresses), resell raw access without permission, or send loads that harm the Service or the official sources behind it. We may limit or block abusive use.

4. No advice, no warranty

Results are not legal or tax advice. You remain responsible for your VAT treatment. The Service is provided "as is"; official sources can be unavailable or wrong, and we do not guarantee uninterrupted availability.

5. Liability

To the extent permitted by law, our liability is limited to the amount you paid for the Service in the 12 months before the claim (zero for the free tier). This does not limit liability that cannot be limited by law, such as for intent or gross negligence.

6. Personal data

See the privacy policy.

7. Changes and law

We may update these terms; the date below shows the current version. Hungarian law applies; mandatory consumer protection rules of your country remain unaffected.

Last updated 2026-10-17.