3 files changed, 21 insertions, 9 deletions
diff --git a/common/src/Common/Message/Key.hs b/common/src/Common/Message/Key.hs
index a6828d5..6e5f246 100644
--- a/common/src/Common/Message/Key.hs
+++ b/common/src/Common/Message/Key.hs
@@ -38,8 +38,8 @@ data Key =
   | Error_SignOut
 
   | Form_AlreadyExists
-  | Form_CostMustNotBeNull
-  | Form_Empty
+  | Form_NonEmpty
+  | Form_NonNullNumber
   | Form_GreaterIntThan Int
   | Form_InvalidCategory
   | Form_InvalidColor
diff --git a/common/src/Common/Message/Translation.hs b/common/src/Common/Message/Translation.hs
index 5ea12ad..70eb978 100644
--- a/common/src/Common/Message/Translation.hs
+++ b/common/src/Common/Message/Translation.hs
@@ -157,16 +157,16 @@ m l Form_AlreadyExists =
     English -> "Dupplicate field"
     French  -> "Doublon"
 
-m l Form_CostMustNotBeNull =
-  case l of
-    English -> "Cost must not be zero"
-    French  -> "Le coût ne doît pas être nul"
-
-m l Form_Empty =
+m l Form_NonEmpty =
   case l of
     English -> "Required field"
     French  -> "Champ requis"
 
+m l Form_NonNullNumber =
+  case l of
+    English -> "Number must not be null"
+    French  -> "Le nombre ne doit pas être nul"
+
 m l (Form_GreaterIntThan number) =
   case l of
     English -> T.concat [ "Integer smaller than ", T.pack . show $ number, " or equal required" ]
diff --git a/common/src/Common/Model/CreatePayment.hs b/common/src/Common/Model/CreatePayment.hs
index cd0b01d..c61423c 100644
--- a/common/src/Common/Model/CreatePayment.hs
+++ b/common/src/Common/Model/CreatePayment.hs
@@ -1,5 +1,6 @@
 module Common.Model.CreatePayment
-  ( CreatePayment(..)
+  ( CreatePaymentError(..)
+  , CreatePayment(..)
   ) where
 
 import           Data.Aeson             (FromJSON, ToJSON)
@@ -10,6 +11,17 @@ import           GHC.Generics           (Generic)
 import           Common.Model.Category  (CategoryId)
 import           Common.Model.Frequency (Frequency)
 
+data CreatePaymentError = CreatePaymentError
+  { _createPaymentError_name      :: Maybe Text
+  , _createPaymentError_cost      :: Maybe Text
+  , _createPaymentError_date      :: Maybe Text
+  , _createPaymentError_category  :: Maybe Text
+  , _createPaymentError_frequency :: Maybe Text
+  } deriving (Show, Generic)
+
+instance FromJSON CreatePaymentError
+instance ToJSON CreatePaymentError
+
 data CreatePayment = CreatePayment
   { _createPayment_name      :: Text
   , _createPayment_cost      :: Int