How localize ErrorMessage in DataAnnotation?

You need to use ErrorMessageResourceName and ErrorMessageResourceType properties.

For example like this:

[Compare("Password", ErrorMessageResourceName = "ConfirmPasswordErrorMessage",
  ErrorMessageResourceType=typeof(<<type_of_your_resoruce_class>>)]
public string ConfirmPassword { get; set; }

Hope this helps!

Regards, Uros