diff --git a/apier/v1/resourcesv1_it_test.go b/apier/v1/resourcesv1_it_test.go
index 6f4b95742..ca1cde0d0 100644
--- a/apier/v1/resourcesv1_it_test.go
+++ b/apier/v1/resourcesv1_it_test.go
@@ -196,7 +196,7 @@ func testV1RsTTL0(t *testing.T) {
 		argsRU, &reply); err != nil {
 		t.Error(err)
 	}
-	// second allocation should be also allowed
+	// overwrite the first allocation
 	argsRU = utils.ArgRSv1ResourceUsage{
 		CGREvent: utils.CGREvent{
 			Tenant: "cgrates.org",
@@ -205,7 +205,7 @@ func testV1RsTTL0(t *testing.T) {
 				"Destination": "3002"},
 		},
 		UsageID: "651a8db2-4f67-4cf8-b622-169e8a482e21",
-		Units:   1,
+		Units:   2,
 	}
 	if err := rlsV1Rpc.Call(utils.ResourceSv1AllocateResources, argsRU, &reply); err != nil {
 		t.Error(err)
@@ -219,13 +219,13 @@ func testV1RsTTL0(t *testing.T) {
 				"Destination": "3002"},
 		},
 		UsageID: "651a8db2-4f67-4cf8-b622-169e8a482e22",
-		Units:   2,
+		Units:   4,
 	}
 	if err := rlsV1Rpc.Call(utils.ResourceSv1AllocateResources, argsRU, &reply); err == nil ||
 		err.Error() != utils.ErrResourceUnavailable.Error() {
 		t.Error(err)
 	}
-	// make sure no usage was recorded
+	// check the record
 	var rs *engine.Resources
 	args := &utils.ArgRSv1ResourceUsage{
 		CGREvent: utils.CGREvent{
@@ -235,6 +235,22 @@ func testV1RsTTL0(t *testing.T) {
 				"Destination": "3002"},
 		},
 	}
+	expiryTime, err := utils.ParseTimeDetectLayout("0001-01-01T00:00:00Z", "")
+	if err != nil {
+		t.Error(err)
+	}
+	expectedResources := &engine.Resource{
+		Tenant: "cgrates.org",
+		ID:     "ResGroup3",
+		Usages: map[string]*engine.ResourceUsage{
+			"651a8db2-4f67-4cf8-b622-169e8a482e21": &engine.ResourceUsage{
+				Tenant:     "cgrates.org",
+				ID:         "651a8db2-4f67-4cf8-b622-169e8a482e21",
+				ExpiryTime: expiryTime,
+				Units:      2,
+			},
+		},
+	}
 	if err := rlsV1Rpc.Call(utils.ResourceSv1GetResourcesForEvent,
 		args, &rs); err != nil {
 		t.Error(err)
@@ -242,8 +258,8 @@ func testV1RsTTL0(t *testing.T) {
 		t.Errorf("Resources: %+v", rs)
 	} else {
 		res := *rs
-		if len(res[0].Usages) != 0 || len(res[0].TTLIdx) != 0 {
-			t.Errorf("Resource should have no usage records in: %+v", res[0])
+		if !reflect.DeepEqual(expectedResources, res[0]) {
+			t.Errorf("Expecting: %+v, received: %+v", expectedResources, res[0])
 		}
 	}
 	// release should not give out errors
diff --git a/data/tariffplans/tutorial/Resources.csv b/data/tariffplans/tutorial/Resources.csv
index 51fb93c84..0f47b20a6 100644
--- a/data/tariffplans/tutorial/Resources.csv
+++ b/data/tariffplans/tutorial/Resources.csv
@@ -1,4 +1,4 @@
 #Tenant[0],Id[1],FilterIDs[2],ActivationInterval[3],TTL[4],Limit[5],AllocationMessage[6],Blocker[7],Stored[8],Weight[9],ThresholdIDs[10]
 cgrates.org,ResGroup1,FLTR_1,2014-07-29T15:00:00Z,1s,7,,false,false,20,
 cgrates.org,ResGroup2,FLTR_DST_FS,2014-07-29T15:00:00Z,3600s,8,SPECIAL_1002,false,true,10,
-cgrates.org,ResGroup3,FLTR_RES_GR3,2014-07-29T15:00:00Z,0s,1,,true,false,20,
+cgrates.org,ResGroup3,FLTR_RES_GR3,2014-07-29T15:00:00Z,*unlimited,3,,true,false,20,
diff --git a/engine/resources.go b/engine/resources.go
index f1a7c3e47..649524e7d 100755
--- a/engine/resources.go
+++ b/engine/resources.go
@@ -148,7 +148,7 @@ func (r *Resource) recordUsage(ru *ResourceUsage) (err error) {
 	if _, hasID := r.Usages[ru.ID]; hasID {
 		return fmt.Errorf("duplicate resource usage with id: %s", ru.TenantID())
 	}
-	if r.ttl != nil {
+	if r.ttl != nil && *r.ttl != -1 {
 		if *r.ttl == 0 {
 			return // no recording for ttl of 0
 		}
@@ -206,7 +206,7 @@ func (rs Resources) recordUsage(ru *ResourceUsage) (err error) {
 	}
 	if err != nil {
 		for _, r := range rs[:nonReservedIdx] {
-			r.clearUsage(ru.TenantID()) // best effort
+			r.clearUsage(ru.ID) // best effort
 		}
 	}
 	return
@@ -254,6 +254,9 @@ func (rs Resources) allocateResource(ru *ResourceUsage, dryRun bool) (alcMessage
 	// Simulate resource usage
 	for _, r := range rs {
 		r.removeExpiredUnits()
+		if _, hasID := r.Usages[ru.ID]; hasID { // update
+			r.clearUsage(ru.ID)
+		}
 		if r.rPrf.Limit >= r.totalUsage()+ru.Units {
 			if alcMessage == "" {
 				if r.rPrf.AllocationMessage != "" {
diff --git a/engine/resources_test.go b/engine/resources_test.go
index d41bb9271..9a0dcb573 100644
--- a/engine/resources_test.go
+++ b/engine/resources_test.go
@@ -336,7 +336,7 @@ func TestRSAllocateResource(t *testing.T) {
 	if alcMessage, err := rs.allocateResource(ru1, true); err != nil {
 		t.Error(err.Error())
 	} else {
-		if alcMessage != "RL2" {
+		if alcMessage != "ALLOC" {
 			t.Errorf("Wrong allocation message: %v", alcMessage)
 		}
 	}
@@ -350,8 +350,8 @@ func TestRSAllocateResource(t *testing.T) {
 	}
 
 	ru2.Units = 0
-	if _, err := rs.allocateResource(ru2, false); err == nil {
-		t.Error("Duplicate ResourceUsage id should not be allowed")
+	if _, err := rs.allocateResource(ru2, false); err != nil {
+		t.Error(err)
 	}
 }
 
diff --git a/utils/coreutils.go b/utils/coreutils.go
index fca396d6a..6101a353d 100644
--- a/utils/coreutils.go
+++ b/utils/coreutils.go
@@ -294,6 +294,9 @@ func ParseDurationWithNanosecs(durStr string) (d time.Duration, err error) {
 	if durStr == "" {
 		return
 	}
+	if durStr == UNLIMITED {
+		durStr = "-1"
+	}
 	if _, err = strconv.ParseFloat(durStr, 64); err == nil { // Seconds format considered
 		durStr += "ns"
 	}