--- trunk/library/Zend/Validate/CreditCard.php	(revision 21561)
+++ trunk/library/Zend/Validate/CreditCard.php	(working copy)
@@ -55,6 +55,7 @@
     const INVALID        = 'creditcardInvalid';
     const LENGTH         = 'creditcardLength';
     const PREFIX         = 'creditcardPrefix';
+    const NOPREFIX       = 'creditcardNoPrefix';
     const SERVICE        = 'creditcardService';
     const SERVICEFAILURE = 'creditcardServiceFailure';
 
@@ -69,6 +70,7 @@
         self::INVALID        => "Invalid type given, value should be a string",
         self::LENGTH         => "'%value%' contains an invalid amount of digits",
         self::PREFIX         => "'%value%' is not from an allowed institute",
+        self::NOPREFIX       => "'%value%' is not from a known institute",
         self::SERVICE        => "Validation of '%value%' has been failed by the service",
         self::SERVICEFAILURE => "The service returned a failure while validating '%value%'",
     );
@@ -258,27 +260,31 @@
         }
 
         $length = strlen($value);
-        $types  = $this->getType();
+        $types  = array_keys($this->_cardLength);
         $found  = false;
         foreach ($types as $type) {
-            if (in_array($length, $this->_cardLength[$type])) {
-                foreach ($this->_cardType[$type] as $prefix) {
-                    if (substr($value, 0, strlen($prefix)) == $prefix) {
-                        $found = true;
-                        break;
-                    }
+            foreach ($this->_cardType[$type] as $prefix) {
+                if (substr($value, 0, strlen($prefix)) == $prefix) {
+                    $found = true;
+                    break 2;
                 }
             }
         }
+        
+        if (false == $found) {
+            $this->_error(self::NOPREFIX, $value);
+            return false;
+        }
+        
+        $allowedTypes  = $this->getType();
+        if (true == $found && !in_array($type, $allowedTypes)) {
+            $this->_error(self::PREFIX, $value);
+            return false;
+        }
 
-        if ($found == false) {
-            if (!in_array($length, $this->_cardLength[$type])) {
-                $this->_error(self::LENGTH, $value);
-                return false;
-            } else {
-                $this->_error(self::PREFIX, $value);
-                return false;
-            }
+        if (true == $found && !in_array($length, $this->_cardLength[$type])) {
+            $this->_error(self::LENGTH, $value);
+            return false;
         }
 
         $sum    = 0;