diff --git a/actions-qrcode.php b/actions-qrcode.php
index fa29d48..198b421 100644
--- a/actions-qrcode.php
+++ b/actions-qrcode.php
@@ -37,16 +37,17 @@ function response($message,$error=0,$log=1)
 
 function rent($userId,$bike,$force=FALSE)
 {
-    global $db, $forcestack, $watches, $credit, $user, $creditSystem;
+    global $db, $forcestack, $watches, $user, $creditSystem;
 
-   $stacktopbike=FALSE;
-   $bikeNum = $bike;
-   $minRequiredCredit = $creditSystem->getMinRequiredCredit();
-
-   $creditcheck=checkrequiredcredit($userId);
-    if ($creditcheck === false) {
+    $stacktopbike=FALSE;
+    $bikeNum = $bike;
+    if (!$creditSystem->isEnoughCreditForRent($userId)) {
+        $minRequiredCredit = $creditSystem->getMinRequiredCredit();
         response(_('You are below required credit') . " " . $minRequiredCredit . $creditSystem->getCreditCurrency() . ". " . _('Please, recharge your credit.'), ERROR);
+
+        return;
     }
+
    checktoomany(0,$userId);
 
    $result=$db->query("SELECT count(*) as countRented FROM bikes where currentUser=$userId");
diff --git a/actions-sms.php b/actions-sms.php
index a19c265..03d9e38 100644
--- a/actions-sms.php
+++ b/actions-sms.php
@@ -111,16 +111,17 @@ function rent($number,$bike,$force=FALSE)
     $stacktopbike = FALSE;
     $userId = $user->findUserIdByNumber($number);
     $bikeNum = intval($bike);
-    $minRequiredCredit = $creditSystem->getMinRequiredCredit();
 
-   if ($force==FALSE)
-           {
-           $creditcheck=checkrequiredcredit($userId);
-           if ($creditcheck === false) {
-               $userRemainingCredit = $creditSystem->getUserCredit($userId);
-               $smsSender->send($number, _('Please, recharge your credit:') . " " . $userRemainingCredit . $creditSystem->getCreditCurrency() . ". " . _('Credit required:') . " " . $minRequiredCredit . $creditSystem->getCreditCurrency() . ".");
-               return;
-           }
+    if ($force == FALSE) {
+        if (!$creditSystem->isEnoughCreditForRent($userId)) {
+            $minRequiredCredit = $creditSystem->getMinRequiredCredit();
+            $userRemainingCredit = $creditSystem->getUserCredit($userId);
+            $smsSender->send(
+                $number,
+                _('Please, recharge your credit:') . " " . $userRemainingCredit . $creditSystem->getCreditCurrency() . ". " . _('Credit required:') . " " . $minRequiredCredit . $creditSystem->getCreditCurrency() . "."
+            );
+            return;
+        }
 
          checktoomany(0,$userId);
 
diff --git a/actions-web.php b/actions-web.php
index aa51a76..c4edd97 100644
--- a/actions-web.php
+++ b/actions-web.php
@@ -32,13 +32,15 @@ function rent($userId, $bike, $force = false)
 
     $stacktopbike = false;
     $bikeNum = $bike;
-    $minRequiredCredit = $creditSystem->getMinRequiredCredit();
 
     if ($force == false) {
-        $creditcheck = checkrequiredcredit($userId);
-        if ($creditcheck === false) {
+        if (!$creditSystem->isEnoughCreditForRent($userId)) {
+            $minRequiredCredit = $creditSystem->getMinRequiredCredit();
             response(_('You are below required credit') . ' ' . $minRequiredCredit . $creditSystem->getCreditCurrency() . '. ' . _('Please, recharge your credit.'), ERROR);
+
+            return;
         }
+
         checktoomany(0, $userId);
 
         $result = $db->query("SELECT count(*) as countRented FROM bikes where currentUser=$userId");
diff --git a/common.php b/common.php
index 1b97a4e..dbe62bf 100644
--- a/common.php
+++ b/common.php
@@ -317,26 +317,6 @@ function checktoomany($cron = 1, $userid = 0)
     }
 }
 
-// check if user has credit >= minimum credit+rent fee+long rental fee
-function checkrequiredcredit($userid)
-{
-    global $creditSystem;
-
-    if ($creditSystem->isEnabled() == false) {
-        return;
-    }
-    // if credit system disabled, exit
-
-    $minRequiredCredit = $creditSystem->getMinRequiredCredit();
-
-    $userRemainingCredit = $creditSystem->getUserCredit($userid);
-    if ($userRemainingCredit >= $minRequiredCredit) {
-        return true;
-    }
-
-    return false;
-}
-
 // subtract credit for rental
 function changecreditendrental($bike, $userid)
 {
diff --git a/src/Credit/CreditSystem.php b/src/Credit/CreditSystem.php
index 987005c..68404d3 100644
--- a/src/Credit/CreditSystem.php
+++ b/src/Credit/CreditSystem.php
@@ -52,6 +52,11 @@ public function getMinRequiredCredit()
         return $this->minBalanceCredit + $this->rentalFee + $this->longRentalFee;
     }
 
+    public function isEnoughCreditForRent($userid)
+    {
+        return $this->getUserCredit($userid) >= $this->getMinRequiredCredit();
+    }
+
     /**
      * @return bool
      */
diff --git a/src/Credit/CreditSystemInterface.php b/src/Credit/CreditSystemInterface.php
index 8d03c92..194578f 100644
--- a/src/Credit/CreditSystemInterface.php
+++ b/src/Credit/CreditSystemInterface.php
@@ -14,6 +14,11 @@ public function getUserCredit($userid);
      */
     public function getMinRequiredCredit();
 
+    /**
+     * @return bool
+     */
+    public function isEnoughCreditForRent($userid);
+
     /**
      * @return bool
      */
diff --git a/src/Credit/DisabledCreditSystem.php b/src/Credit/DisabledCreditSystem.php
index 25fb454..2978b7a 100644
--- a/src/Credit/DisabledCreditSystem.php
+++ b/src/Credit/DisabledCreditSystem.php
@@ -14,6 +14,11 @@ public function getMinRequiredCredit()
         return PHP_INT_MAX;
     }
 
+    public function isEnoughCreditForRent($userid)
+    {
+        return true;
+    }
+
     public function isEnabled()
     {
         return false;