diff --git a/go-backend/internal/controllers/membershipController.go b/go-backend/internal/controllers/membershipController.go
index 19c0441..5fadcb6 100644
--- a/go-backend/internal/controllers/membershipController.go
+++ b/go-backend/internal/controllers/membershipController.go
@@ -32,12 +32,12 @@ func (mc *MembershipController) RegisterSubscription(c *gin.Context) {
 
 	requestUser, err := mc.UserController.ExtractUserFromContext(c)
 	if err != nil {
-		utils.RespondWithError(c, err, "Error extracting user from context in subscription registrationHandler", http.StatusBadRequest, "general", "server.validation.invalid_user_data")
+		utils.RespondWithError(c, err, "Error extracting user from context in subscription registrationHandler", http.StatusBadRequest, errors.Responses.Fields.User, errors.Responses.Keys.NoAuthToken)
 		return
 	}
 
 	if !utils.HasPrivilige(requestUser, constants.Priviliges.Create) {
-		utils.RespondWithError(c, errors.ErrNotAuthorized, "Not allowed to register subscription", http.StatusForbidden, "user.user", "server.error.unauthorized")
+		utils.RespondWithError(c, errors.ErrNotAuthorized, "Not allowed to register subscription", http.StatusForbidden, errors.Responses.Fields.User, errors.Responses.Keys.Unauthorized)
 		return
 	}
 
@@ -47,15 +47,13 @@ func (mc *MembershipController) RegisterSubscription(c *gin.Context) {
 	}
 
 	// Register Subscription
-	logger.Info.Printf("Registering subscription %v", regData.Subscription.Name)
 	id, err := mc.Service.RegisterSubscription(&regData.Subscription)
 	if err != nil {
-		logger.Error.Printf("Couldn't register Membershipmodel: %v", err)
 		if strings.Contains(err.Error(), "UNIQUE constraint failed") {
-			c.JSON(http.StatusConflict, "Duplicate subscription name")
-			return
+			utils.RespondWithError(c, err, "Subscription already exists", http.StatusConflict, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.Duplicate)
+		} else {
+			utils.RespondWithError(c, err, "Couldn't register Membershipmodel", http.StatusInternalServerError, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.InternalServerError)
 		}
-		c.JSON(http.StatusNotAcceptable, "Couldn't register Membershipmodel")
 		return
 	}
 	logger.Info.Printf("registering subscription: %+v", regData)
@@ -70,12 +68,12 @@ func (mc *MembershipController) UpdateHandler(c *gin.Context) {
 
 	requestUser, err := mc.UserController.ExtractUserFromContext(c)
 	if err != nil {
-		utils.RespondWithError(c, err, "Error extracting user from context in subscription UpdateHandler", http.StatusBadRequest, "general", "server.validation.no_auth_tokenw")
+		utils.RespondWithError(c, err, "Error extracting user from context in subscription Updatehandler", http.StatusBadRequest, errors.Responses.Fields.User, errors.Responses.Keys.NoAuthToken)
 		return
 	}
 
 	if !utils.HasPrivilige(requestUser, constants.Priviliges.Update) {
-		utils.RespondWithError(c, errors.ErrNotAuthorized, "Not allowed to update subscription", http.StatusForbidden, "user.user", "server.error.unauthorized")
+		utils.RespondWithError(c, errors.ErrNotAuthorized, "Not allowed to update subscription", http.StatusForbidden, errors.Responses.Fields.User, errors.Responses.Keys.Unauthorized)
 		return
 	}
 
@@ -88,12 +86,15 @@ func (mc *MembershipController) UpdateHandler(c *gin.Context) {
 	logger.Info.Printf("Updating subscription %v", regData.Subscription.Name)
 	id, err := mc.Service.UpdateSubscription(&regData.Subscription)
 	if err != nil {
-		logger.Error.Printf("Couldn't update Membershipmodel: %v", err)
 		if strings.Contains(err.Error(), "UNIQUE constraint failed") {
-			c.JSON(http.StatusConflict, "Duplicate subscription name")
-			return
+			utils.RespondWithError(c, err, "Subscription already exists", http.StatusConflict, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.Duplicate)
+		} else if err == errors.ErrSubscriptionNotFound {
+			utils.RespondWithError(c, err, "Subscription not found", http.StatusNotFound, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.NotFound)
+		} else if err == errors.ErrInvalidSubscriptionData {
+			utils.RespondWithError(c, err, "Invalid subscription data", http.StatusBadRequest, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.Invalid)
+		} else {
+			utils.RespondWithError(c, err, "Couldn't update subscription", http.StatusInternalServerError, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.InternalServerError)
 		}
-		c.JSON(http.StatusNotAcceptable, "Couldn't update Membershipmodel")
 		return
 	}
 	logger.Info.Printf("updating subscription: %+v", regData)
@@ -114,12 +115,12 @@ func (mc *MembershipController) DeleteSubscription(c *gin.Context) {
 	var data deleteData
 	requestUser, err := mc.UserController.ExtractUserFromContext(c)
 	if err != nil {
-		utils.RespondWithError(c, err, "Error extracting user from context in subscription UpdateHandler", http.StatusBadRequest, "general", "server.validation.no_auth_tokenw")
+		utils.RespondWithError(c, err, "Error extracting user from context in subscription deleteSubscription", http.StatusBadRequest, errors.Responses.Fields.User, errors.Responses.Keys.NoAuthToken)
 		return
 	}
 
 	if !utils.HasPrivilige(requestUser, constants.Priviliges.Delete) {
-		utils.RespondWithError(c, errors.ErrNotAuthorized, "Not allowed to update subscription", http.StatusForbidden, "user.user", "server.error.unauthorized")
+		utils.RespondWithError(c, errors.ErrNotAuthorized, "Not allowed to update subscription", http.StatusForbidden, errors.Responses.Fields.User, errors.Responses.Keys.Unauthorized)
 		return
 	}
 
@@ -129,7 +130,17 @@ func (mc *MembershipController) DeleteSubscription(c *gin.Context) {
 	}
 
 	if err := mc.Service.DeleteSubscription(&data.Subscription.ID, &data.Subscription.Name); err != nil {
-		utils.RespondWithError(c, err, "Error during subscription Deletion", http.StatusExpectationFailed, "subscription", "server.error.not_possible")
+		if err == errors.ErrNoData {
+			utils.RespondWithError(c, err, "Missing subscription name during deletion", http.StatusExpectationFailed, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.Invalid)
+		} else if err == errors.ErrNotFound {
+			utils.RespondWithError(c, err, "Subscription not found", http.StatusNotFound, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.NotFound)
+		} else if err == errors.ErrInvalidSubscriptionData {
+			utils.RespondWithError(c, err, "Invalid subscription data", http.StatusBadRequest, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.Invalid)
+		} else if err == errors.ErrSubscriptionInUse {
+			utils.RespondWithError(c, err, "Subscription is in use by at least one user", http.StatusExpectationFailed, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.InUse)
+		} else {
+			utils.RespondWithError(c, err, "Error during subscription Deletion", http.StatusInternalServerError, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.InternalServerError)
+		}
 		return
 	}
 
@@ -139,11 +150,7 @@ func (mc *MembershipController) DeleteSubscription(c *gin.Context) {
 func (mc *MembershipController) GetSubscriptions(c *gin.Context) {
 	subscriptions, err := mc.Service.GetSubscriptions(nil)
 	if err != nil {
-		logger.Error.Printf("Error retrieving subscriptions: %v", err)
-		c.JSON(http.StatusInternalServerError, gin.H{"errors": []gin.H{{
-			"field": "general",
-			"key":   "validation.internal_server_error",
-		}}})
+		utils.RespondWithError(c, err, "Error retrieving subscriptions", http.StatusInternalServerError, errors.Responses.Fields.SubscriptionModel, errors.Responses.Keys.InternalServerError)
 		return
 	}