diff --git a/src/main/java/fr/unistra/sil/erp/back/controller/api/ApiSubmitTransactionController.java b/src/main/java/fr/unistra/sil/erp/back/controller/api/ApiSubmitTransactionController.java
index a2498691b8ff74f34371df466e7169b794170499..37189f0370ae9e38725a92824cdfaffd27dcf65b 100644
--- a/src/main/java/fr/unistra/sil/erp/back/controller/api/ApiSubmitTransactionController.java
+++ b/src/main/java/fr/unistra/sil/erp/back/controller/api/ApiSubmitTransactionController.java
@@ -60,8 +60,7 @@ public class ApiSubmitTransactionController
         if(t == null)
             throw new ApiBadRequestException("Missing JSON body.");
         
-        if(t.getItem() == null || t.getType() == null ||
-                t.getAmount() == null)
+        if(!t.checkIfValid())
             throw new ApiBadRequestException("Invalid JSON schema.");
         
         System.out.println("Transaction : " + t.getItem() +
diff --git a/src/main/java/fr/unistra/sil/erp/back/model/Transaction.java b/src/main/java/fr/unistra/sil/erp/back/model/Transaction.java
index 19dae4eb45214466dde67a5dae3998ab02cdf489..b4eadecb89526c673987a594a6b23b2c5cf71c3e 100644
--- a/src/main/java/fr/unistra/sil/erp/back/model/Transaction.java
+++ b/src/main/java/fr/unistra/sil/erp/back/model/Transaction.java
@@ -18,11 +18,15 @@ public class Transaction {
     
     private final BigDecimal amount;
     
-    public Transaction(Integer item, Integer type, BigDecimal amount)
+    private final Integer quantity;
+    
+    public Transaction(Integer item, Integer type, BigDecimal amount,
+            Integer quantity)
     {
         this.item = item;
         this.type = type;
         this.amount = amount;
+        this.quantity = quantity;
     }
     
     public Integer getItem()
@@ -40,4 +44,15 @@ public class Transaction {
         return this.amount;
     }
     
+    public Integer getQuantity()
+    {
+        return this.quantity;
+    }
+    
+    public boolean checkIfValid()
+    {
+        return (this.item != null && this.type != null
+                && this.amount != null && this.quantity != null);
+    }
+    
 }