diff --git a/sessionmanager/data_it_test.go b/sessionmanager/data_it_test.go
index d3804dfcf..826f8653c 100644
--- a/sessionmanager/data_it_test.go
+++ b/sessionmanager/data_it_test.go
@@ -115,7 +115,7 @@ func TestSMGDataLastUsedData(t *testing.T) {
 	if maxUsage != 1.048576e+06 {
 		t.Error("Bad max usage: ", maxUsage)
 	}
-	eAcntVal = 49998951424.000000
+	eAcntVal = 49998945280.000000
 	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
 		t.Error(err)
 	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
@@ -141,7 +141,7 @@ func TestSMGDataLastUsedData(t *testing.T) {
 	if maxUsage != 1.048576e+06 {
 		t.Error("Bad max usage: ", maxUsage)
 	}
-	eAcntVal = 49998931424.000000
+	eAcntVal = 49998924800.000000
 	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
 		t.Error(err)
 	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
@@ -164,7 +164,178 @@ func TestSMGDataLastUsedData(t *testing.T) {
 	if err = smgRPC.Call("SMGenericV1.SessionEnd", smgEv, &rpl); err != nil || rpl != utils.OK {
 		t.Error(err)
 	}
-	eAcntVal = 49998931424.000000
+	eAcntVal = 49999979520.000000
+	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
+		t.Error(err)
+	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
+		t.Errorf("Expected: %f, received: %f", eAcntVal, acnt.BalanceMap[utils.DATA].GetTotalValue())
+	}
+}
+
+func TestSMGDataLastUsedMultipleData(t *testing.T) {
+	if !*testIntegration {
+		return
+	}
+	var acnt *engine.Account
+	attrs := &utils.AttrGetAccount{Tenant: "cgrates.org", Account: "1010"}
+	eAcntVal := 49999979520.000000
+	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
+		t.Error(err)
+	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
+		t.Errorf("Expected: %f, received: %f", eAcntVal, acnt.BalanceMap[utils.DATA].GetTotalValue())
+	}
+	smgEv := SMGenericEvent{
+		utils.EVENT_NAME:  "TEST_EVENT",
+		utils.TOR:         utils.DATA,
+		utils.ACCID:       "12349",
+		utils.DIRECTION:   utils.OUT,
+		utils.ACCOUNT:     "1010",
+		utils.SUBJECT:     "1010",
+		utils.DESTINATION: "222",
+		utils.CATEGORY:    "data",
+		utils.TENANT:      "cgrates.org",
+		utils.REQTYPE:     utils.META_PREPAID,
+		utils.SETUP_TIME:  "2016-01-05 18:30:49",
+		utils.ANSWER_TIME: "2016-01-05 18:31:05",
+		utils.USAGE:       "1048576",
+	}
+	var maxUsage float64
+	if err := smgRPC.Call("SMGenericV1.SessionStart", smgEv, &maxUsage); err != nil {
+		t.Error(err)
+	}
+	if maxUsage != 1.048576e+06 {
+		t.Error("Bad max usage: ", maxUsage)
+	}
+	eAcntVal = 49998924800.000000
+	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
+		t.Error(err)
+	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
+		t.Errorf("Expected: %f, received: %f", eAcntVal, acnt.BalanceMap[utils.DATA].GetTotalValue())
+	}
+	smgEv = SMGenericEvent{
+		utils.EVENT_NAME:  "TEST_EVENT",
+		utils.TOR:         utils.DATA,
+		utils.ACCID:       "12349",
+		utils.DIRECTION:   utils.OUT,
+		utils.ACCOUNT:     "1010",
+		utils.SUBJECT:     "1010",
+		utils.DESTINATION: "222",
+		utils.CATEGORY:    "data",
+		utils.TENANT:      "cgrates.org",
+		utils.REQTYPE:     utils.META_PREPAID,
+		utils.USAGE:       "1048576",
+		utils.LastUsed:    "20000",
+	}
+	if err := smgRPC.Call("SMGenericV1.SessionUpdate", smgEv, &maxUsage); err != nil {
+		t.Error(err)
+	}
+	if maxUsage != 1.048576e+06 {
+		t.Error("Bad max usage: ", maxUsage)
+	}
+	eAcntVal = 49998904320.000000
+	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
+		t.Error(err)
+	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
+		t.Errorf("Expected: %f, received: %f", eAcntVal, acnt.BalanceMap[utils.DATA].GetTotalValue())
+	}
+	smgEv = SMGenericEvent{
+		utils.EVENT_NAME:  "TEST_EVENT",
+		utils.TOR:         utils.DATA,
+		utils.ACCID:       "12349",
+		utils.DIRECTION:   utils.OUT,
+		utils.ACCOUNT:     "1010",
+		utils.SUBJECT:     "1010",
+		utils.DESTINATION: "222",
+		utils.CATEGORY:    "data",
+		utils.TENANT:      "cgrates.org",
+		utils.REQTYPE:     utils.META_PREPAID,
+		utils.USAGE:       "1048576",
+		utils.LastUsed:    "20000",
+	}
+	if err := smgRPC.Call("SMGenericV1.SessionUpdate", smgEv, &maxUsage); err != nil {
+		t.Error(err)
+	}
+	if maxUsage != 1.048576e+06 {
+		t.Error("Bad max usage: ", maxUsage)
+	}
+	eAcntVal = 49998883840.000000
+	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
+		t.Error(err)
+	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
+		t.Errorf("Expected: %f, received: %f", eAcntVal, acnt.BalanceMap[utils.DATA].GetTotalValue())
+	}
+
+	smgEv = SMGenericEvent{
+		utils.EVENT_NAME:  "TEST_EVENT",
+		utils.TOR:         utils.DATA,
+		utils.ACCID:       "12349",
+		utils.DIRECTION:   utils.OUT,
+		utils.ACCOUNT:     "1010",
+		utils.SUBJECT:     "1010",
+		utils.DESTINATION: "222",
+		utils.CATEGORY:    "data",
+		utils.TENANT:      "cgrates.org",
+		utils.REQTYPE:     utils.META_PREPAID,
+		utils.USAGE:       "1048576",
+		utils.LastUsed:    "20000",
+	}
+	if err := smgRPC.Call("SMGenericV1.SessionUpdate", smgEv, &maxUsage); err != nil {
+		t.Error(err)
+	}
+	if maxUsage != 1.048576e+06 {
+		t.Error("Bad max usage: ", maxUsage)
+	}
+	eAcntVal = 49998904320.000000
+	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
+		t.Error(err)
+	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
+		t.Errorf("Expected: %f, received: %f", eAcntVal, acnt.BalanceMap[utils.DATA].GetTotalValue())
+	}
+	smgEv = SMGenericEvent{
+		utils.EVENT_NAME:  "TEST_EVENT",
+		utils.TOR:         utils.DATA,
+		utils.ACCID:       "12349",
+		utils.DIRECTION:   utils.OUT,
+		utils.ACCOUNT:     "1010",
+		utils.SUBJECT:     "1010",
+		utils.DESTINATION: "222",
+		utils.CATEGORY:    "data",
+		utils.TENANT:      "cgrates.org",
+		utils.REQTYPE:     utils.META_PREPAID,
+		utils.USAGE:       "1048576",
+		utils.LastUsed:    "20000",
+	}
+	if err := smgRPC.Call("SMGenericV1.SessionUpdate", smgEv, &maxUsage); err != nil {
+		t.Error(err)
+	}
+	if maxUsage != 1.048576e+06 {
+		t.Error("Bad max usage: ", maxUsage)
+	}
+	eAcntVal = 49998883840.000000
+	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
+		t.Error(err)
+	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
+		t.Errorf("Expected: %f, received: %f", eAcntVal, acnt.BalanceMap[utils.DATA].GetTotalValue())
+	}
+
+	smgEv = SMGenericEvent{
+		utils.EVENT_NAME:  "TEST_EVENT",
+		utils.TOR:         utils.DATA,
+		utils.ACCID:       "12349",
+		utils.DIRECTION:   utils.OUT,
+		utils.ACCOUNT:     "1010",
+		utils.SUBJECT:     "1010",
+		utils.DESTINATION: "222",
+		utils.CATEGORY:    "data",
+		utils.TENANT:      "cgrates.org",
+		utils.REQTYPE:     utils.META_PREPAID,
+		utils.LastUsed:    "0",
+	}
+	var rpl string
+	if err = smgRPC.Call("SMGenericV1.SessionEnd", smgEv, &rpl); err != nil || rpl != utils.OK {
+		t.Error(err)
+	}
+	eAcntVal = 49999948800.000000
 	if err := smgRPC.Call("ApierV2.GetAccount", attrs, &acnt); err != nil {
 		t.Error(err)
 	} else if acnt.BalanceMap[utils.DATA].GetTotalValue() != eAcntVal {
diff --git a/sessionmanager/smg_session.go b/sessionmanager/smg_session.go
index 936f4ac56..6eace1506 100644
--- a/sessionmanager/smg_session.go
+++ b/sessionmanager/smg_session.go
@@ -88,7 +88,7 @@ func (self *SMGSession) debit(dur time.Duration, lastUsed time.Duration) (time.D
 
 		// apply the lastUsed correction
 		dur += lastUsedCorrection
-		self.totalUsage += dur // Should reflect the total usage so far
+		self.totalUsage += lastUsed // Should reflect the total usage so far
 	} else {
 		// apply correction from previous run
 		dur -= self.extraDuration