diff --git a/services/character/character.go b/services/character/character.go
index c946879..1913306 100644
--- a/services/character/character.go
+++ b/services/character/character.go
@@ -3,7 +3,7 @@ package characterapi
 import (
 	"context"
 	character "crossnokaye-interview-assignment/services/character/gen/character"
-	"errors"
+	"fmt"
 	"log"
 )
 
@@ -26,8 +26,8 @@ func (s *charactersrvc) GetCharacter(ctx context.Context, p *character.GetCharac
 
 	itemToGet := (*s.characters)[*p.Name]
 	if itemToGet == nil {
-		s.logger.Printf("character with id %d not found", &p.Name)
-		return nil, errors.New("character not found")
+		s.logger.Printf("character with id '%s' not found", *p.Name)
+		return nil, character.MakeNotFound(fmt.Errorf("character with id '%s' not found", *p.Name))
 	}
 	res = (*s.characters)[*p.Name]
 
@@ -47,8 +47,8 @@ func (s *charactersrvc) CreateCharacter(ctx context.Context, p *character.Charac
 
 	existingCharacter := (*s.characters)[p.Name]
 	if existingCharacter != nil {
-		s.logger.Printf("character with name %d already exists", &p.Name)
-		return nil, errors.New("character already exists")
+		s.logger.Printf("character with name %s already exists", p.Name)
+		return nil, character.MakeAlreadyExists(fmt.Errorf("character with name %s already exists", p.Name))
 	}
 
 	(*s.characters)[p.Name] = p
@@ -62,8 +62,8 @@ func (s *charactersrvc) UpdateCharacter(ctx context.Context, p *character.Charac
 
 	itemToUpdate := (*s.characters)[p.Name]
 	if itemToUpdate == nil {
-		s.logger.Printf("characters with id %d not found", &p.Name)
-		return nil, errors.New("characters not found")
+		s.logger.Printf("character with id '%s' not found", p.Name)
+		return nil, character.MakeNotFound(fmt.Errorf("character with id '%s' not found", p.Name))
 	}
 	(*s.characters)[p.Name] = p
 	res = (*s.characters)[p.Name]
@@ -77,11 +77,11 @@ func (s *charactersrvc) DeleteCharacter(ctx context.Context, p *character.Delete
 
 	itemToDelete := (*s.characters)[*p.Name]
 	if itemToDelete == nil {
-		s.logger.Printf("characters with id %d not found", &p.Name)
-		return errors.New("characters not found")
+		s.logger.Printf("character with id '%s' not found", *p.Name)
+		return character.MakeNotFound(fmt.Errorf("character with id '%s' not found", *p.Name))
 	}
 
-	delete((*s.characters), *p.Name)
+	delete(*s.characters, *p.Name)
 
 	return
 }
diff --git a/services/character/design/design.go b/services/character/design/design.go
index 6230074..3d8978b 100644
--- a/services/character/design/design.go
+++ b/services/character/design/design.go
@@ -24,12 +24,10 @@ var _ = Service("character", func() {
 		})
 		Result(Character)
 		Error("NotFound")
-		Error("BadRequest")
 
 		GRPC(func() {
 			Response(CodeOK)
 			Response("NotFound", CodeNotFound)
-			Response("BadRequest", CodeInvalidArgument)
 		})
 	})
 
@@ -45,13 +43,13 @@ var _ = Service("character", func() {
 	Method("createCharacter", func() {
 		Payload(Character)
 		Result(Character)
-		Error("BadRequest")
 		Error("NotFound")
+		Error("AlreadyExists")
 
 		GRPC(func() {
 			Response(CodeOK)
 			Response("NotFound", CodeNotFound)
-			Response("BadRequest", CodeInvalidArgument)
+			Response("AlreadyExists", CodeAlreadyExists)
 		})
 	})
 
@@ -59,12 +57,10 @@ var _ = Service("character", func() {
 		Payload(Character)
 		Result(Character)
 		Error("NotFound")
-		Error("BadRequest")
 
 		GRPC(func() {
 			Response(CodeOK)
 			Response("NotFound", CodeNotFound)
-			Response("BadRequest", CodeInvalidArgument)
 		})
 	})
 
@@ -74,12 +70,10 @@ var _ = Service("character", func() {
 		})
 		Result(Empty)
 		Error("NotFound")
-		Error("BadRequest")
 
 		GRPC(func() {
 			Response(CodeOK)
 			Response("NotFound", CodeNotFound)
-			Response("BadRequest", CodeInvalidArgument)
 		})
 	})
 })
diff --git a/services/front/design/design.go b/services/front/design/design.go
index 9006b7b..0b4a556 100644
--- a/services/front/design/design.go
+++ b/services/front/design/design.go
@@ -27,8 +27,7 @@ var _ = Service("front", func() {
 		HTTP(func() {
 			GET("/item/{name}")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -39,20 +38,18 @@ var _ = Service("front", func() {
 		HTTP(func() {
 			GET("/item")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
 		})
 	})
 
 	Method("createItem", func() {
 		Payload(Item)
 		Result(Item)
-		Error("BadRequest")
+		Error("AlreadyExists")
 
 		HTTP(func() {
 			POST("/item")
 			Response(StatusOK)
-			Response(StatusBadRequest)
+			Response("AlreadyExists", StatusConflict)
 		})
 	})
 
@@ -60,13 +57,11 @@ var _ = Service("front", func() {
 		Payload(Item)
 		Result(Item)
 		Error("NotFound")
-		Error("BadRequest")
 
 		HTTP(func() {
 			PUT("/item/{name}")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -74,13 +69,11 @@ var _ = Service("front", func() {
 		Payload(String)
 		Result(Empty)
 		Error("NotFound")
-		Error("BadRequest")
 
 		HTTP(func() {
 			DELETE("/item/{name}")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -88,13 +81,11 @@ var _ = Service("front", func() {
 		Payload(String)
 		Result(Character)
 		Error("NotFound")
-		Error("BadRequest")
 
 		HTTP(func() {
 			GET("/character/{name}")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -105,22 +96,18 @@ var _ = Service("front", func() {
 		HTTP(func() {
 			GET("/character")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
 		})
 	})
 
 	Method("createCharacter", func() {
 		Payload(Character)
 		Result(Character)
-		Error("BadRequest")
 		Error("NotFound")
 
 		HTTP(func() {
 			POST("/character")
 			Response(StatusBadRequest)
-			Response(StatusOK)
-			Response(StatusInternalServerError)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -128,13 +115,11 @@ var _ = Service("front", func() {
 		Payload(Character)
 		Result(Character)
 		Error("NotFound")
-		Error("BadRequest")
 
 		HTTP(func() {
 			PUT("/character/{name}")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -142,13 +127,11 @@ var _ = Service("front", func() {
 		Payload(String)
 		Result(Empty)
 		Error("NotFound")
-		Error("BadRequest")
 
 		HTTP(func() {
 			DELETE("/character/{name}")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -156,12 +139,11 @@ var _ = Service("front", func() {
 		Payload(InventoryRecord)
 		Result(Empty)
 		Error("NotFound")
-		Error("BadRequest")
 
 		HTTP(func() {
 			POST("/character/{characterName}/item")
 			Response(StatusOK)
-			Response(StatusBadRequest)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -169,12 +151,11 @@ var _ = Service("front", func() {
 		Payload(InventoryRecord)
 		Result(Empty)
 		Error("NotFound")
-		Error("BadRequest")
 
 		HTTP(func() {
 			DELETE("/character/{characterName}/item/{itemName}")
 			Response(StatusOK)
-			Response(StatusBadRequest)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
@@ -183,12 +164,12 @@ var _ = Service("front", func() {
 			Field(1, "characterName", String)
 		})
 		Result(ArrayOf(Item))
+		Error("NotFound")
 
 		HTTP(func() {
 			GET("/character/{characterName}/item")
 			Response(StatusOK)
-			Response(StatusBadRequest)
-			Response(StatusNotFound)
+			Response("NotFound", StatusNotFound)
 		})
 	})
 
diff --git a/services/inventory/design/design.go b/services/inventory/design/design.go
index ded878e..a2a567c 100644
--- a/services/inventory/design/design.go
+++ b/services/inventory/design/design.go
@@ -30,8 +30,6 @@ var _ = Service("inventory", func() {
 	Method("addItem", func() {
 		Payload(design.InventoryRecord)
 		Result(Empty)
-		Error("NotFound")
-		Error("BadRequest")
 
 		GRPC(func() {
 			Response(CodeOK)
@@ -42,12 +40,10 @@ var _ = Service("inventory", func() {
 		Payload(design.InventoryRecord)
 		Result(Empty)
 		Error("NotFound")
-		Error("BadRequest")
 
 		GRPC(func() {
 			Response(CodeOK)
 			Response("NotFound", CodeNotFound)
-			Response("BadRequest", CodeInvalidArgument)
 		})
 	})
 })
diff --git a/services/inventory/inventory.go b/services/inventory/inventory.go
index 8b59102..e624e9f 100644
--- a/services/inventory/inventory.go
+++ b/services/inventory/inventory.go
@@ -3,7 +3,7 @@ package inventoryapi
 import (
 	"context"
 	inventory "crossnokaye-interview-assignment/services/inventory/gen/inventory"
-	"errors"
+	"fmt"
 	"log"
 )
 
@@ -40,8 +40,8 @@ func (s *inventorysrvc) RemoveItem(ctx context.Context, p *inventory.InventoryRe
 
 	itemList := (*s.inventories)[p.CharacterName]
 	if itemList == nil {
-		s.logger.Printf("inventory for character with id %d not found", p.CharacterName)
-		return errors.New("item not found")
+		s.logger.Printf("inventory for character with name '%s' not found", p.CharacterName)
+		return inventory.MakeNotFound(fmt.Errorf("inventory for character with name '%s' not found", p.CharacterName))
 	}
 
 	idx := indexOf(p.ItemName, *itemList)
@@ -49,8 +49,9 @@ func (s *inventorysrvc) RemoveItem(ctx context.Context, p *inventory.InventoryRe
 		newItemList := remove(*itemList, idx)
 		(*s.inventories)[p.CharacterName] = &newItemList
 	} else {
-		s.logger.Printf("character with id %d does not have item %d in inventory", p.CharacterName, p.ItemName)
-		return errors.New("item not found for character")
+		s.logger.Printf("character with name '%s' does not have item '%s' in inventory", p.CharacterName, p.ItemName)
+		return inventory.MakeNotFound(fmt.Errorf("character with name '%s' does not have item '%s' in inventory",
+			p.CharacterName, p.ItemName))
 	}
 
 	return
diff --git a/services/item/design/design.go b/services/item/design/design.go
index 0f73237..2b64143 100644
--- a/services/item/design/design.go
+++ b/services/item/design/design.go
@@ -27,6 +27,7 @@ var _ = Service("item", func() {
 
 		GRPC(func() {
 			Response(CodeOK)
+			Response("NotFound", CodeNotFound)
 		})
 	})
 
@@ -44,10 +45,11 @@ var _ = Service("item", func() {
 	Method("createItem", func() {
 		Payload(Item)
 		Result(Item)
-		Error("BadRequest")
+		Error("AlreadyExists")
 
 		GRPC(func() {
 			Response(CodeOK)
+			Response("AlreadyExists", CodeAlreadyExists)
 		})
 	})
 
@@ -55,10 +57,10 @@ var _ = Service("item", func() {
 		Payload(Item)
 		Result(Item)
 		Error("NotFound")
-		Error("BadRequest")
 
 		GRPC(func() {
 			Response(CodeOK)
+			Response("NotFound", CodeNotFound)
 		})
 	})
 
@@ -68,12 +70,10 @@ var _ = Service("item", func() {
 		})
 		Result(Empty)
 		Error("NotFound")
-		Error("BadRequest")
 
 		GRPC(func() {
 			Response(CodeOK)
 			Response("NotFound", CodeNotFound)
-			Response("BadRequest", CodeInvalidArgument)
 		})
 	})
 })
diff --git a/services/item/item.go b/services/item/item.go
index e5ad8e7..7901c74 100644
--- a/services/item/item.go
+++ b/services/item/item.go
@@ -3,7 +3,7 @@ package itemapi
 import (
 	"context"
 	item "crossnokaye-interview-assignment/services/item/gen/item"
-	"errors"
+	"fmt"
 	"log"
 )
 
@@ -26,8 +26,8 @@ func (s *itemsrvc) GetItem(ctx context.Context, p *item.GetItemPayload) (res *it
 
 	itemToGet := (*s.items)[*p.Name]
 	if itemToGet == nil {
-		s.logger.Printf("item with id %d not found", &p.Name)
-		return nil, errors.New("item not found")
+		s.logger.Printf("item with name '%s' not found", *p.Name)
+		return nil, item.MakeNotFound(fmt.Errorf("item with name '%s' not found", *p.Name))
 	}
 	res = (*s.items)[*p.Name]
 
@@ -55,8 +55,8 @@ func (s *itemsrvc) CreateItem(ctx context.Context, p *item.Item) (res *item.Item
 
 	existingItem := (*s.items)[name]
 	if existingItem != nil {
-		s.logger.Printf("item with name %d already exists", &p.Name)
-		return nil, errors.New("item already exists")
+		s.logger.Printf("item with name '%s' already exists", p.Name)
+		return nil, item.MakeAlreadyExists(fmt.Errorf("item with name '%s' already exists", p.Name))
 	}
 
 	(*s.items)[name] = p
@@ -70,8 +70,8 @@ func (s *itemsrvc) UpdateItem(ctx context.Context, p *item.Item) (res *item.Item
 	s.logger.Print("itemToGet.updateItem")
 	itemToUpdate := (*s.items)[p.Name]
 	if itemToUpdate == nil {
-		s.logger.Printf("item with id %d not found", &p.Name)
-		return nil, errors.New("item not found")
+		s.logger.Printf("item with name '%s' not found", p.Name)
+		return nil, item.MakeNotFound(fmt.Errorf("item with name '%s' not found", p.Name))
 	}
 	(*s.items)[p.Name] = p
 	res = (*s.items)[p.Name]
@@ -84,11 +84,11 @@ func (s *itemsrvc) DeleteItem(ctx context.Context, p *item.DeleteItemPayload) (e
 	s.logger.Print("item.deleteItem")
 	itemToDelete := (*s.items)[*p.Name]
 	if itemToDelete == nil {
-		s.logger.Printf("item with id %d not found", &p.Name)
-		return errors.New("item not found")
+		s.logger.Printf("item with name '%s' not found", *p.Name)
+		return item.MakeNotFound(fmt.Errorf("item with name '%s' not found", *p.Name))
 	}
 
-	delete((*s.items), *p.Name)
+	delete(*s.items, *p.Name)
 
 	return
 }