diff --git a/engine/account.go b/engine/account.go
index 89bdecef1..5f7b0eba4 100644
--- a/engine/account.go
+++ b/engine/account.go
@@ -1161,7 +1161,7 @@ func NewAccountSummaryFromJSON(jsn string) (acntSummary *AccountSummary, err err
 type AccountSummary struct {
 	Tenant           string
 	ID               string
-	BalanceSummaries []*BalanceSummary
+	BalanceSummaries BalanceSummaries
 	AllowNegative    bool
 	Disabled         bool
 }
@@ -1173,7 +1173,7 @@ func (as *AccountSummary) Clone() (cln *AccountSummary) {
 	cln.AllowNegative = as.AllowNegative
 	cln.Disabled = as.Disabled
 	if as.BalanceSummaries != nil {
-		cln.BalanceSummaries = make([]*BalanceSummary, len(as.BalanceSummaries))
+		cln.BalanceSummaries = make(BalanceSummaries, len(as.BalanceSummaries))
 		for i, bs := range as.BalanceSummaries {
 			cln.BalanceSummaries[i] = new(BalanceSummary)
 			*cln.BalanceSummaries[i] = *bs
diff --git a/engine/balances.go b/engine/balances.go
index 3d789c75a..c0675af85 100644
--- a/engine/balances.go
+++ b/engine/balances.go
@@ -896,3 +896,16 @@ type BalanceSummary struct {
 	Value    float64
 	Disabled bool
 }
+
+type BalanceSummaries []*BalanceSummary
+
+// GetBalanceSummary returns a BalanceSummary based on an UUID
+func (bs BalanceSummaries) BalanceSummaryWithUUD(bsUUID string) (b *BalanceSummary) {
+	for _, blc := range bs {
+		if blc.UUID == bsUUID {
+			b = blc
+			break
+		}
+	}
+	return
+}
diff --git a/engine/cdrs.go b/engine/cdrs.go
index 64f1e736b..57b77c1a5 100644
--- a/engine/cdrs.go
+++ b/engine/cdrs.go
@@ -286,6 +286,11 @@ func (cdrS *CDRServer) rateCDRWithErr(cdr *CDRWithArgDispatcher) (ratedCDRs []*C
 	return
 }
 
+func (cdrS *CDRServer) refundCDR(cdr *CDR) (err error) {
+
+	return
+}
+
 // chrgProcessEvent will process the CGREvent with ChargerS subsystem
 // it is designed to run in it's own goroutine
 func (cdrS *CDRServer) chrgProcessEvent(cgrEv *utils.CGREventWithArgDispatcher,
diff --git a/engine/eventcost.go b/engine/eventcost.go
index a702f0dc5..8f6333a36 100644
--- a/engine/eventcost.go
+++ b/engine/eventcost.go
@@ -254,6 +254,62 @@ func (ec *EventCost) ComputeEventCostUsageIndexes() {
 	}
 }
 
+// AsCallDescriptor converts an EventCost into a CallDescriptor
+func (ec *EventCost) AsRefundIncrements(tor string) (cd *CallDescriptor) {
+	cd = &CallDescriptor{
+		CgrID:         ec.CGRID,
+		RunID:         ec.RunID,
+		TOR:           tor,
+		TimeStart:     ec.StartTime,
+		TimeEnd:       ec.StartTime.Add(ec.GetUsage()),
+		DurationIndex: ec.GetUsage(),
+	}
+	if len(ec.Charges) == 0 {
+		return
+	}
+	var nrIcrms int
+	for _, cIl := range ec.Charges {
+		nrIcrms += (cIl.CompressFactor * len(cIl.Increments))
+	}
+	cd.Increments = make(Increments, nrIcrms)
+	var iIdx int
+	for _, cIl := range ec.Charges {
+		for i := 0; i < cIl.CompressFactor; i++ {
+			for _, cIcrm := range cIl.Increments {
+				cd.Increments[iIdx] = &Increment{
+					Cost:           cIcrm.Cost,
+					Duration:       cIcrm.Usage,
+					CompressFactor: cIcrm.CompressFactor,
+				}
+				if cIcrm.AccountingID != utils.EmptyString {
+					cd.Increments[iIdx].BalanceInfo = &DebitInfo{
+						AccountID: ec.Accounting[cIcrm.AccountingID].AccountID,
+					}
+					blncSmry := ec.AccountSummary.BalanceSummaries.BalanceSummaryWithUUD(ec.Accounting[cIcrm.AccountingID].BalanceUUID)
+					if blncSmry.Type == utils.MONETARY {
+						cd.Increments[iIdx].BalanceInfo.Monetary = &MonetaryInfo{UUID: blncSmry.UUID}
+					} else if NonMonetaryBalances.HasField(blncSmry.Type) {
+						cd.Increments[iIdx].BalanceInfo.Unit = &UnitInfo{UUID: blncSmry.UUID}
+					}
+					if ec.Accounting[cIcrm.AccountingID].ExtraChargeID == utils.META_NONE ||
+						ec.Accounting[cIcrm.AccountingID].ExtraChargeID == utils.EmptyString {
+						continue
+					}
+					// extra charges, ie: non-free *voice
+					extraSmry := ec.AccountSummary.BalanceSummaries.BalanceSummaryWithUUD(ec.Accounting[cIcrm.AccountingID].ExtraChargeID)
+					if extraSmry.Type == utils.MONETARY {
+						cd.Increments[iIdx].BalanceInfo.Monetary = &MonetaryInfo{UUID: extraSmry.UUID}
+					} else if NonMonetaryBalances.HasField(blncSmry.Type) {
+						cd.Increments[iIdx].BalanceInfo.Unit = &UnitInfo{UUID: extraSmry.UUID}
+					}
+				}
+			}
+		}
+	}
+	return
+}
+
+// AsCallCost converts an EventCost into a CallCost
 func (ec *EventCost) AsCallCost() *CallCost {
 	cc := &CallCost{
 		Cost: ec.GetCost(), RatedUsage: float64(ec.GetUsage().Nanoseconds()),
@@ -271,10 +327,10 @@ func (ec *EventCost) AsCallCost() *CallCost {
 		if cIl.RatingID != "" {
 			if ec.Rating[cIl.RatingID].RatingFiltersID != "" {
 				rfs := ec.RatingFilters[ec.Rating[cIl.RatingID].RatingFiltersID]
-				ts.MatchedSubject = rfs["Subject"].(string)
-				ts.MatchedPrefix = rfs["DestinationPrefix"].(string)
-				ts.MatchedDestId = rfs["DestinationID"].(string)
-				ts.RatingPlanId = rfs["RatingPlanID"].(string)
+				ts.MatchedSubject = rfs[utils.Subject].(string)
+				ts.MatchedPrefix = rfs[utils.DestinationPrefix].(string)
+				ts.MatchedDestId = rfs[utils.DestinationID].(string)
+				ts.RatingPlanId = rfs[utils.RatingPlanID].(string)
 			}
 		}
 		ts.RateInterval = ec.rateIntervalForRatingID(cIl.RatingID)
diff --git a/engine/libeventcost.go b/engine/libeventcost.go
index 5d9c48109..613bb0403 100644
--- a/engine/libeventcost.go
+++ b/engine/libeventcost.go
@@ -27,6 +27,14 @@ import (
 	"github.com/cgrates/cgrates/utils"
 )
 
+// NonMonetaryBalances are types of balances which are not handled as monetary
+var NonMonetaryBalances = MapEvent{
+	utils.VOICE:   struct{}{},
+	utils.SMS:     struct{}{},
+	utils.DATA:    struct{}{},
+	utils.GENERIC: struct{}{},
+}
+
 // ChargingInterval represents one interval out of Usage providing charging info
 // eg: PEAK vs OFFPEAK
 type ChargingInterval struct {
diff --git a/utils/consts.go b/utils/consts.go
index f60704671..5b8e10f7a 100755
--- a/utils/consts.go
+++ b/utils/consts.go
@@ -548,6 +548,8 @@ const (
 	UUID                        = "UUID"
 	ActionsID                   = "ActionsID"
 	MetaAct                     = "*act"
+	DestinationPrefix           = "DestinationPrefix"
+	DestinationID               = "DestinationID"
 )
 
 // Migrator Action