diff --git a/core/lib/Thelia/Coupon/Type/CouponAbstract.php b/core/lib/Thelia/Coupon/Type/CouponAbstract.php
index 9766b7fbe..a0bdf2db1 100644
--- a/core/lib/Thelia/Coupon/Type/CouponAbstract.php
+++ b/core/lib/Thelia/Coupon/Type/CouponAbstract.php
@@ -183,6 +183,7 @@ abstract class CouponAbstract implements CouponInterface
 
     /**
      * @param true $perCustomerUsageCount
+     * @return $this
      */
     public function setPerCustomerUsageCount($perCustomerUsageCount)
     {
@@ -425,14 +426,14 @@ abstract class CouponAbstract implements CouponInterface
      * This methods checks a field value. If the field has a correct value, this value is returned
      * Otherwise, an InvalidArgumentException describing the problem should be thrown.
      *
-     * This method should be ovveriden to be useful.
+     * This method should be overriden to be useful.
      *
-     * @param $fieldName
-     * @param $fieldValue
+     * @param string $fieldName
+     * @param string $fieldValue
      * @return mixed
-     * @throws \InvalidArgumentException if the field valiue is not valid.
+     * @throws \InvalidArgumentException if the field value is not valid.
      */
-    protected function checkCouponFieldValue($fieldName, $fieldValue)
+    protected function checkCouponFieldValue(/** @noinspection PhpUnusedParameterInspection */ $fieldName, $fieldValue)
     {
         return $fieldValue;
     }
@@ -507,4 +508,11 @@ abstract class CouponAbstract implements CouponInterface
     {
         // Does nothing. Override this function as needed.
     }
+
+    public function isInUse() {
+        return in_array(
+            $this->code,
+            $this->facade->getRequest()->getSession()->getConsumedCoupons()
+        );
+    }
 }
diff --git a/core/lib/Thelia/Coupon/Type/CouponInterface.php b/core/lib/Thelia/Coupon/Type/CouponInterface.php
index d8190f3d7..cfd645d28 100644
--- a/core/lib/Thelia/Coupon/Type/CouponInterface.php
+++ b/core/lib/Thelia/Coupon/Type/CouponInterface.php
@@ -192,15 +192,15 @@ interface CouponInterface
     public function isExpired();
 
     /**
-     * Return effects generated by the coupon
-     * A positive value
+     * Return an amount thant will be subtracted to the cart total, or zero.
      *
-     * Effects could also affect something else than the final Checkout price
-     * FacadeInterface $facade could be used to directly pass a Session value
-     * some would wish to modify
-     * Hence affecting a wide variety of Thelia elements
+     * This method could also perform something else than the calculating an amount to subtract from the cart. It may
+     * add a product to the cart, for example. In this case, an amount of 0 will be returned.
      *
-     * @return float Amount removed from the Total Checkout
+     * WARNING: this method could be called several times, so perform suitable checks before performing cart
+     * manipulations, so that the coupon effect will not be applied several times.
+     *
+     * @return float Amount removed from the cart total
      */
     public function exec();
 
@@ -244,4 +244,8 @@ interface CouponInterface
      */
     public function clear();
 
+    /**
+     * @return bool true if the coupon is currently in use in the current order process, false otherwise
+     */
+    public function isInUse();
 }