diff --git a/lib/streaming_providers/base/provider.py b/lib/streaming_providers/base/provider.py
index 219dc37..3f789e9 100644
--- a/lib/streaming_providers/base/provider.py
+++ b/lib/streaming_providers/base/provider.py
@@ -27,6 +27,8 @@ class StreamingProvider(ABC):
     Abstract base class for streaming providers with centralized HTTP and auth management
     """
 
+    SUPPORTED_COUNTRIES: List[str] = []
+
     def __init__(self, country: str = 'DE'):
         self.country = country
         self.channels: List[StreamingChannel] = []
@@ -697,4 +699,42 @@ class StreamingProvider(ABC):
         else:
             # Default to query parameters
             separator = '&' if '?' in base_url else '?'
-            return f"{base_url}{separator}start={start_time}&end={end_time}"
\ No newline at end of file
+            return f"{base_url}{separator}start={start_time}&end={end_time}"
+
+    @classmethod
+    def get_supported_countries(cls) -> List[str]:
+        """
+        Get list of countries supported by this provider.
+
+        Returns:
+            List of ISO country codes (e.g., ['de', 'at', 'ch'])
+            Empty list means single-country provider using default country
+        """
+        return cls.SUPPORTED_COUNTRIES.copy()
+
+    @classmethod
+    def supports_multiple_countries(cls) -> bool:
+        """
+        Check if this provider supports multiple countries.
+
+        Returns:
+            True if provider supports country-specific instances
+        """
+        return len(cls.SUPPORTED_COUNTRIES) > 0
+
+    @classmethod
+    def validate_country(cls, country: str) -> bool:
+        """
+        Validate if a country is supported by this provider.
+
+        Args:
+            country: ISO country code to validate
+
+        Returns:
+            True if country is supported or provider is single-country
+        """
+        if not cls.supports_multiple_countries():
+            # Single-country providers accept any country (or ignore it)
+            return True
+
+        return country.lower() in [c.lower() for c in cls.SUPPORTED_COUNTRIES]
\ No newline at end of file
diff --git a/lib/streaming_providers/providers/joyn/provider.py b/lib/streaming_providers/providers/joyn/provider.py
index ea34a3e..44c13b1 100644
--- a/lib/streaming_providers/providers/joyn/provider.py
+++ b/lib/streaming_providers/providers/joyn/provider.py
@@ -89,6 +89,13 @@ class JoynProvider(StreamingProvider):
             proxy_config: Optional proxy configuration (highest priority)
             proxy_url: Optional proxy URL string (medium priority)
         """
+        if not self.validate_country(country):
+            supported = ', '.join(self.SUPPORTED_COUNTRIES)
+            raise ValueError(
+                f"Unsupported country: {country}. "
+                f"Joyn supports: {supported}"
+            )
+
         super().__init__(country=country)
 
         if country not in SUPPORTED_COUNTRIES:
diff --git a/lib/streaming_providers/providers/magentaeu/provider.py b/lib/streaming_providers/providers/magentaeu/provider.py
index 87ffdff..77bfa50 100644
--- a/lib/streaming_providers/providers/magentaeu/provider.py
+++ b/lib/streaming_providers/providers/magentaeu/provider.py
@@ -39,6 +39,12 @@ class MagentaProvider(StreamingProvider):
                  proxy_url: Optional[str] = None):
 
         logger.info(f"=== MagentaProvider.__init__ START for country: {country} ===")
+        if not self.validate_country(country):
+            supported = ', '.join(self.SUPPORTED_COUNTRIES)
+            raise ValueError(
+                f"Unsupported country: {country}. "
+                f"MagentaTV EU supports: {supported}"
+            )
         super().__init__(country=country)
 
         if country not in SUPPORTED_COUNTRIES:
@@ -474,7 +480,7 @@ class MagentaProvider(StreamingProvider):
             logger.debug(f"Credential validation failed: {e}")
             return False
 
-    @staticmethod
-    def get_supported_countries() -> List[str]:
+    @classmethod
+    def get_supported_countries(cls) -> List[str]:
         """Get list of supported countries"""
-        return SUPPORTED_COUNTRIES.copy()
\ No newline at end of file
+        return cls.SUPPORTED_COUNTRIES.copy()
\ No newline at end of file