MS_UNAVAILABLE
Member state VAT service is unavailable
What does MS_UNAVAILABLE mean?
The MS_UNAVAILABLE error means the VAT validation service for a specific EU member state is currently offline. VIES couldn't connect to that country's national database to verify the VAT number.
Each EU country maintains its own VAT registration database, and VIES acts as a gateway to these national systems. When a country's system is down for maintenance or experiencing technical issues, you'll get this error.
When does this error occur?
- During scheduled maintenance windows (often nights and weekends)
- When a country's national VAT system has technical problems
- During infrastructure upgrades or migrations
- Some countries have regular, predictable downtime; others are sporadic
Common maintenance patterns
Some member states have known maintenance windows:
| Country | Typical Maintenance |
|---|---|
| Germany (DE) | Frequent unplanned outages |
| Italy (IT) | Weekend maintenance common |
| France (FR) | Generally reliable |
| Spain (ES) | Occasional evening maintenance |
Note: These patterns change and aren't officially published by the EU.
Outages can last hours
How to handle MS_UNAVAILABLE
1. Use a service with multiple data sources
VatDB queries multiple official EU and national databases. When a member state is unavailable through VIES, we can often validate through their national system directly. Set up webhooks to get notified when validation succeeds after a source becomes available again.
2. Don't retry aggressively
Unlike rate limits, service outages don't clear quickly. Aggressive retries waste resources. Wait at least 5 to 10 minutes before retrying.
3. Implement a circuit breaker
After several failures for a country, stop trying and fail fast. Use cached results or queue for later processing.
Validate even when countries are offline
VatDB maintains connections to multiple official EU and national databases. When a member state is unavailable through VIES, we query alternative sources directly. Get validation results even during VIES outages, and use webhooks to handle async validation when services recover.
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