Using the InvariantCulture Property

It is associated with the English language but not with a country or region.  

The CultureInfo.InvariantCulture property is neither a neutral nor a specific culture. It is a third type of culture that is culture-insensitive. You can use InvariantCulture in almost any method in the System.Globalization namespace that requires a culture. 

When should we use it?

• You should use the invariant culture only for processes that require culture-independent results, such as system services. In other cases, it produces results that might be linguistically incorrect or culturally inappropriate.

• You should also use InvariantCulture when a security decision will be made based on the result of a string comparison or case change. 

The default implementations of methods such as String.Compare, String.ToUpper, and String.ToLower use the CultureInfo.CurrentCulture property. 

When we shouldn't use it?

• Code that performs culture-sensitive string operations can cause security vulnerabilities.
  

• if CultureInfo.CurrentCulture is changed or if the culture on the computer on which the code runs differs from the culture the developer used to test the code, the expected behavior of a string operation will differ from the actual behavior on the computer running that operation. 

Best Practices

To eliminate cultural variations and ensure consistent results regardless of the value of CultureInfo.CurrentCulture, use overloads of the String.Compare, String.ToUpper and String.ToLower methods that accept a CultureInfo parameter and specify the CultureInfo.InvariantCulture property for the CultureInfo parameter.

For more information about using the InvariantCulture property to perform culture-insensitive string operations, see Culture-InsensitiveString Operations.