diff --git a/agents/agentreq.go b/agents/agentreq.go
index 440d7deb8..07b58d729 100644
--- a/agents/agentreq.go
+++ b/agents/agentreq.go
@@ -432,10 +432,21 @@ func (ar *AgentRequest) ParseField(
 		out = strconv.Itoa(int(t.Unix()))
 	case utils.MetaSIPCID:
 		isString = true
-		values := make([]string, len(cfgFld.Value))
-		for i, val := range cfgFld.Value {
-			if values[i], err = val.ParseDataProvider(ar, utils.NestingSep); err != nil {
-				return nil, err
+		values := make([]string, 1, len(cfgFld.Value))
+		if len(cfgFld.Value) < 1 {
+			return nil, fmt.Errorf("invalid number of arguments <%s> to %s",
+				utils.ToJSON(cfgFld.Value), utils.MetaSIPCID)
+		}
+		if values[0], err = cfgFld.Value[0].ParseDataProvider(ar, utils.NestingSep); err != nil {
+			return
+		}
+		for _, val := range cfgFld.Value[1:] {
+			var valStr string
+			if valStr, err = val.ParseDataProvider(ar, utils.NestingSep); err != nil && err != utils.ErrNotFound {
+				return
+			}
+			if len(valStr) != 0 && err != utils.ErrNotFound {
+				values = append(values, valStr)
 			}
 		}
 		sort.Strings(values[1:])
diff --git a/engine/attributes.go b/engine/attributes.go
index 0cabe01f2..97ebf97bb 100644
--- a/engine/attributes.go
+++ b/engine/attributes.go
@@ -248,11 +248,22 @@ func (alS *AttributeService) processEvent(args *AttrArgsProcessEvent) (
 			substitute = strconv.FormatFloat(utils.Round(val*math.Pow10(exp),
 				config.CgrConfig().GeneralCfg().RoundingDecimals, utils.ROUNDING_MIDDLE), 'f', -1, 64)
 		case utils.MetaSIPCID:
-			values := make([]string, len(attribute.Value))
-			for i, val := range attribute.Value {
-				if values[i], err = val.ParseDataProvider(evNm, utils.NestingSep); err != nil {
+			values := make([]string, 1, len(attribute.Value))
+			if len(attribute.Value) < 1 {
+				return nil, fmt.Errorf("invalid number of arguments <%s> to %s",
+					utils.ToJSON(attribute.Value), utils.MetaSIPCID)
+			}
+			if values[0], err = attribute.Value[0].ParseDataProvider(evNm, utils.NestingSep); err != nil {
+				return nil, err
+			}
+			for _, val := range attribute.Value[1:] {
+				var valStr string
+				if valStr, err = val.ParseDataProvider(evNm, utils.NestingSep); err != nil && err != utils.ErrNotFound {
 					return nil, err
 				}
+				if len(valStr) != 0 && err != utils.ErrNotFound {
+					values = append(values, valStr)
+				}
 			}
 			sort.Strings(values[1:])
 			substitute = strings.Join(values, utils.INFIELD_SEP)