diff --git a/sessions/sessions.go b/sessions/sessions.go
index 6be890eeb..68a30d729 100644
--- a/sessions/sessions.go
+++ b/sessions/sessions.go
@@ -1149,6 +1149,7 @@ func (sS *SessionS) transitSState(cgrID string, psv bool) (s *Session) {
 		return
 	}
 	s = ss[0]
+	s.Lock()
 	sS.unregisterSession(cgrID, !psv)
 	sS.registerSession(s, psv)
 	if !psv {
@@ -1157,6 +1158,7 @@ func (sS *SessionS) transitSState(cgrID string, psv bool) (s *Session) {
 		s.stopSTerminator()
 		s.stopDebitLoops()
 	}
+	s.Unlock()
 	return
 }
 
@@ -1639,8 +1641,8 @@ func (sS *SessionS) BiRPCv1SetPassiveSession(clnt rpcclient.ClientConnector,
 	if aSs := sS.getSessions(s.CGRID, false); len(aSs) != 0 { // found active session, transit to passive
 		aSs[0].Lock()
 		sS.unregisterSession(s.CGRID, false)
-		s.stopSTerminator()
-		s.stopDebitLoops()
+		aSs[0].stopSTerminator()
+		aSs[0].stopDebitLoops()
 		aSs[0].Unlock()
 	}
 	sS.registerSession(s, true)
@@ -2179,7 +2181,10 @@ func (sS *SessionS) BiRPCv1InitiateSession(clnt rpcclient.ClientConnector,
 		if err != nil {
 			return err
 		}
-		if s.debitStop != nil { //active debit
+		s.RLock() // avoid concurrency with activeDebit
+		isPrepaid := s.debitStop != nil
+		s.RUnlock()
+		if isPrepaid { //active debit
 			rply.MaxUsage = sS.cgrCfg.SessionSCfg().MaxCallDuration
 		} else {
 			var maxUsage time.Duration
@@ -3127,7 +3132,10 @@ func (sS *SessionS) BiRPCv1ProcessEvent(clnt rpcclient.ClientConnector,
 				if err != nil {
 					return err
 				}
-				if s.debitStop != nil { //active debit
+				s.RLock()
+				isPrepaid := s.debitStop != nil
+				s.RUnlock()
+				if isPrepaid { //active debit
 					rply.MaxUsage = sS.cgrCfg.SessionSCfg().MaxCallDuration
 				} else {
 					var maxUsage time.Duration