diff --git a/src/Authentication/Exception/ValidationException.php b/src/Authentication/Exception/ValidationException.php
index 463899c..faaa73d 100644
--- a/src/Authentication/Exception/ValidationException.php
+++ b/src/Authentication/Exception/ValidationException.php
@@ -4,6 +4,11 @@
 
 class ValidationException extends AuthenticationException
 {
+    public static function missingPersonalCodeAndPhoneNumber()
+    {
+        return new static('Please enter personal code or phone number.');
+    }
+
     public static function invalidPersonalCode($personalCode, $chars = 11)
     {
         return new static(
diff --git a/src/Authentication/MobileID/AuthenticationService.php b/src/Authentication/MobileID/AuthenticationService.php
index 3f5fe40..83931ec 100644
--- a/src/Authentication/MobileID/AuthenticationService.php
+++ b/src/Authentication/MobileID/AuthenticationService.php
@@ -31,18 +31,19 @@ class AuthenticationService extends AbstractService
      * @param  string $language
      * @param  string $serviceName
      * @param  string $displayMessage
+     * @param  boolean $returnCertData
+     * @param  boolean $returnRevocationData
      * @return AuthenticateResponse on successful query.
      * @throws AuthenticationException
      * @throws ServiceException
      * @throws ValidationException
      */
-    public function mobileAuthenticate($personalCode, $phoneNumber, $language, $serviceName, $displayMessage)
+    public function mobileAuthenticate($personalCode, $phoneNumber, $language, $serviceName, $displayMessage, $returnCertData = false, $returnRevocationData = false)
     {
         $this->throwIfSoapNotInitialized();
 
         $this->log(Logger::INFO, '')->log(Logger::INFO, 'SOAP::MobileAuthenticate start validation');
-        $this->validatePersonalCode($personalCode);
-        $this->validatePhoneNumber($phoneNumber);
+        $this->validatePersonalCodeAndPhoneNumber($personalCode, $phoneNumber);
         $this->validateLanguage($language);
         $this->validateServiceName($serviceName);
         $this->validateDisplayMessage($displayMessage);
@@ -50,14 +51,16 @@ public function mobileAuthenticate($personalCode, $phoneNumber, $language, $serv
 
         try {
             $data = [
-                'IDCode'           => $personalCode,
-                'CountryCode'      => self::COUNTRY_CODE_ESTONIA,
-                'PhoneNo'          => $phoneNumber,
-                'Language'         => $language,
-                'ServiceName'      => $serviceName,
-                'MessageToDisplay' => $displayMessage,
-                'SPChallenge'      => $this->generateRandomNumbers(20),
-                'MessagingMode'    => 'asynchClientServer'
+                'IDCode'               => $personalCode,
+                'CountryCode'          => self::COUNTRY_CODE_ESTONIA,
+                'PhoneNo'              => $phoneNumber,
+                'Language'             => $language,
+                'ServiceName'          => $serviceName,
+                'MessageToDisplay'     => $displayMessage,
+                'SPChallenge'          => $this->generateRandomNumbers(20),
+                'MessagingMode'        => 'asynchClientServer',
+                'ReturnCertData'       => ($returnCertData == true),
+                'ReturnRevocationData' => ($returnRevocationData == true)
             ];
 
             $this->log(Logger::INFO, $this->wsdl . ' SOAP::MobileAuthenticate request: ' . serialize($data));
@@ -126,6 +129,21 @@ protected function getHydrator()
         return (new ClassMethods())->setUnderscoreSeparatedKeys(false);
     }
 
+    // Validate that either personalCode or phoneNumber is present
+    protected function validatePersonalCodeAndPhoneNumber($personalCode, $phoneNumber) {
+        if (!isset($personalCode) && !isset($phoneNumber)) {
+            throw ValidationException::missingPersonalCodeAndPhoneNumber();
+        }
+
+        if (isset($personalCode)) {
+            $this->validatePersonalCode($personalCode);
+        }
+
+        if (isset($phoneNumber)) {
+            $this->validatePhoneNumber($phoneNumber);
+        }
+    }
+
     protected function validatePersonalCode($personalCode)
     {
         if (strlen($personalCode) !== 11 || !is_numeric($personalCode)) {