diff --git a/engine/attributes.go b/engine/attributes.go
index a728932a5..cfc2da9c1 100644
--- a/engine/attributes.go
+++ b/engine/attributes.go
@@ -269,7 +269,7 @@ func (alS *AttributeService) processEvent(args *AttrArgsProcessEvent) (
 func (alS *AttributeService) V1GetAttributeForEvent(args *AttrArgsProcessEvent,
 	attrPrfl *AttributeProfile) (err error) {
 	if args.CGREvent == nil {
-		return utils.NewErrMandatoryIeMissing("CGREvent")
+		return utils.NewErrMandatoryIeMissing(utils.CGREventString)
 	}
 	attrPrf, err := alS.attributeProfileForEvent(args)
 	if err != nil {
@@ -284,8 +284,11 @@ func (alS *AttributeService) V1GetAttributeForEvent(args *AttrArgsProcessEvent,
 
 func (alS *AttributeService) V1ProcessEvent(args *AttrArgsProcessEvent,
 	reply *AttrSProcessEventReply) (err error) {
-	if args.CGREvent == nil || args.Event == nil {
-		return utils.NewErrMandatoryIeMissing("Event")
+	if args.CGREvent == nil {
+		return utils.NewErrMandatoryIeMissing(utils.CGREventString)
+	}
+	if args.Event == nil {
+		return utils.NewErrMandatoryIeMissing(utils.Event)
 	}
 	if args.ProcessRuns == nil || *args.ProcessRuns == 0 {
 		args.ProcessRuns = utils.IntPointer(alS.processRuns)
diff --git a/engine/stats.go b/engine/stats.go
index b24c2f8b7..e6180d8b3 100644
--- a/engine/stats.go
+++ b/engine/stats.go
@@ -311,10 +311,13 @@ func (sS *StatService) processEvent(args *StatsArgsProcessEvent) (statQueueIDs [
 
 // V1ProcessEvent implements StatV1 method for processing an Event
 func (sS *StatService) V1ProcessEvent(args *StatsArgsProcessEvent, reply *[]string) (err error) {
-	if missing := utils.MissingStructFields(args, []string{"Tenant", "ID"}); len(missing) != 0 { //Params missing
+	if args.CGREvent == nil {
+		return utils.NewErrMandatoryIeMissing(utils.CGREventString)
+	}
+	if missing := utils.MissingStructFields(args, []string{utils.Tenant, utils.ID}); len(missing) != 0 { //Params missing
 		return utils.NewErrMandatoryIeMissing(missing...)
-	} else if args.CGREvent == nil || args.Event == nil {
-		return utils.NewErrMandatoryIeMissing("Event")
+	} else if args.Event == nil {
+		return utils.NewErrMandatoryIeMissing(utils.Event)
 	}
 	if ids, err := sS.processEvent(args); err != nil {
 		return err
@@ -326,10 +329,13 @@ func (sS *StatService) V1ProcessEvent(args *StatsArgsProcessEvent, reply *[]stri
 
 // V1StatQueuesForEvent implements StatV1 method for processing an Event
 func (sS *StatService) V1GetStatQueuesForEvent(args *StatsArgsProcessEvent, reply *[]string) (err error) {
-	if missing := utils.MissingStructFields(args, []string{"Tenant", "ID"}); len(missing) != 0 { //Params missing
+	if args.CGREvent == nil {
+		return utils.NewErrMandatoryIeMissing(utils.CGREventString)
+	}
+	if missing := utils.MissingStructFields(args, []string{utils.Tenant, utils.ID}); len(missing) != 0 { //Params missing
 		return utils.NewErrMandatoryIeMissing(missing...)
-	} else if args.CGREvent == nil || args.Event == nil {
-		return utils.NewErrMandatoryIeMissing("Event")
+	} else if args.Event == nil {
+		return utils.NewErrMandatoryIeMissing(utils.Event)
 	}
 	var sQs StatQueues
 	if sQs, err = sS.matchingStatQueuesForEvent(args); err != nil {
@@ -346,7 +352,7 @@ func (sS *StatService) V1GetStatQueuesForEvent(args *StatsArgsProcessEvent, repl
 
 // V1GetQueueStringMetrics returns the metrics of a Queue as string values
 func (sS *StatService) V1GetQueueStringMetrics(args *utils.TenantID, reply *map[string]string) (err error) {
-	if missing := utils.MissingStructFields(args, []string{"Tenant", "ID"}); len(missing) != 0 { //Params missing
+	if missing := utils.MissingStructFields(args, []string{utils.Tenant, utils.ID}); len(missing) != 0 { //Params missing
 		return utils.NewErrMandatoryIeMissing(missing...)
 	}
 	sq, err := sS.dm.GetStatQueue(args.Tenant, args.ID, true, true, "")
@@ -368,7 +374,7 @@ func (sS *StatService) V1GetQueueStringMetrics(args *utils.TenantID, reply *map[
 
 // V1GetFloatMetrics returns the metrics as float64 values
 func (sS *StatService) V1GetQueueFloatMetrics(args *utils.TenantID, reply *map[string]float64) (err error) {
-	if missing := utils.MissingStructFields(args, []string{"Tenant", "ID"}); len(missing) != 0 { //Params missing
+	if missing := utils.MissingStructFields(args, []string{utils.Tenant, utils.ID}); len(missing) != 0 { //Params missing
 		return utils.NewErrMandatoryIeMissing(missing...)
 	}
 	sq, err := sS.dm.GetStatQueue(args.Tenant, args.ID, true, true, "")
diff --git a/engine/suppliers.go b/engine/suppliers.go
index 9f5bc27dd..d7a7b8bed 100644
--- a/engine/suppliers.go
+++ b/engine/suppliers.go
@@ -489,12 +489,12 @@ type optsGetSuppliers struct {
 // V1GetSupplierProfilesForEvent returns the list of valid supplier IDs
 func (spS *SupplierService) V1GetSuppliers(args *ArgsGetSuppliers, reply *SortedSuppliers) (err error) {
 	if args.CGREvent == nil {
-		return utils.NewErrMandatoryIeMissing(utils.Event)
+		return utils.NewErrMandatoryIeMissing(utils.CGREventString)
 	}
-	if missing := utils.MissingStructFields(args.CGREvent, []string{"Tenant", "ID"}); len(missing) != 0 {
+	if missing := utils.MissingStructFields(args.CGREvent, []string{utils.Tenant, utils.ID}); len(missing) != 0 {
 		return utils.NewErrMandatoryIeMissing(missing...)
 	} else if args.CGREvent.Event == nil {
-		return utils.NewErrMandatoryIeMissing("Event")
+		return utils.NewErrMandatoryIeMissing(utils.Event)
 	}
 	if spS.attributeS != nil {
 		attrArgs := &AttrArgsProcessEvent{
@@ -523,10 +523,10 @@ func (spS *SupplierService) V1GetSuppliers(args *ArgsGetSuppliers, reply *Sorted
 
 // V1GetSupplierProfiles returns the list of valid supplier profiles
 func (spS *SupplierService) V1GetSupplierProfilesForEvent(args *utils.CGREventWithArgDispatcher, reply *[]*SupplierProfile) (err error) {
-	if missing := utils.MissingStructFields(args.CGREvent, []string{"Tenant", "ID"}); len(missing) != 0 {
+	if missing := utils.MissingStructFields(args.CGREvent, []string{utils.Tenant, utils.ID}); len(missing) != 0 {
 		return utils.NewErrMandatoryIeMissing(missing...)
 	} else if args.CGREvent.Event == nil {
-		return utils.NewErrMandatoryIeMissing("Event")
+		return utils.NewErrMandatoryIeMissing(utils.Event)
 	}
 	sPs, err := spS.matchingSupplierProfilesForEvent(args.CGREvent, false)
 	if err != nil {
diff --git a/engine/thresholds.go b/engine/thresholds.go
index 91abe20ab..3ef0e9f13 100644
--- a/engine/thresholds.go
+++ b/engine/thresholds.go
@@ -340,10 +340,13 @@ func (tS *ThresholdService) processEvent(args *ArgsProcessEvent) (thresholdsIDs
 
 // V1ProcessEvent implements ThresholdService method for processing an Event
 func (tS *ThresholdService) V1ProcessEvent(args *ArgsProcessEvent, reply *[]string) (err error) {
-	if missing := utils.MissingStructFields(args, []string{"Tenant", "ID"}); len(missing) != 0 { //Params missing
+	if args.CGREvent == nil {
+		return utils.NewErrMandatoryIeMissing(utils.CGREventString)
+	}
+	if missing := utils.MissingStructFields(args, []string{utils.Tenant, utils.ID}); len(missing) != 0 { //Params missing
 		return utils.NewErrMandatoryIeMissing(missing...)
-	} else if args.CGREvent == nil || args.CGREvent.Event == nil {
-		return utils.NewErrMandatoryIeMissing("Event")
+	} else if args.CGREvent.Event == nil {
+		return utils.NewErrMandatoryIeMissing(utils.Event)
 	}
 	if ids, err := tS.processEvent(args); err != nil {
 		return err
@@ -355,10 +358,13 @@ func (tS *ThresholdService) V1ProcessEvent(args *ArgsProcessEvent, reply *[]stri
 
 // V1GetThresholdsForEvent queries thresholds matching an Event
 func (tS *ThresholdService) V1GetThresholdsForEvent(args *ArgsProcessEvent, reply *Thresholds) (err error) {
-	if missing := utils.MissingStructFields(args, []string{"Tenant", "ID"}); len(missing) != 0 { //Params missing
+	if args.CGREvent == nil {
+		return utils.NewErrMandatoryIeMissing(utils.CGREventString)
+	}
+	if missing := utils.MissingStructFields(args, []string{utils.Tenant, utils.ID}); len(missing) != 0 { //Params missing
 		return utils.NewErrMandatoryIeMissing(missing...)
-	} else if args.CGREvent == nil || args.CGREvent.Event == nil {
-		return utils.NewErrMandatoryIeMissing("Event")
+	} else if args.CGREvent.Event == nil {
+		return utils.NewErrMandatoryIeMissing(utils.Event)
 	}
 	var ts Thresholds
 	if ts, err = tS.matchingThresholdsForEvent(args); err == nil {
diff --git a/utils/consts.go b/utils/consts.go
index 2a5bd35ca..d0013c809 100755
--- a/utils/consts.go
+++ b/utils/consts.go
@@ -584,6 +584,7 @@ const (
 	PasiveSessionPrefix          = "psv"
 	ApierV                       = "ApierV"
 	MetaApier                    = "*apier"
+	CGREventString               = "CGREvent"
 )
 
 // Migrator Action