diff --git a/charger/ocpp/connector.go b/charger/ocpp/connector.go
index 87512b0fe6..fe8eaada40 100644
--- a/charger/ocpp/connector.go
+++ b/charger/ocpp/connector.go
@@ -31,7 +31,8 @@ type Connector struct {
 	txnId int
 	idTag string
 
-	remoteIdTag string
+	remoteIdTag   string
+	remoteStarted bool // guards RemoteStartTransaction to once per auth cycle
 
 	meterInterval time.Duration
 }
diff --git a/charger/ocpp/connector_core.go b/charger/ocpp/connector_core.go
index 6d4a5ab6b5..55ec07aa2a 100644
--- a/charger/ocpp/connector_core.go
+++ b/charger/ocpp/connector_core.go
@@ -48,19 +48,26 @@ func (conn *Connector) OnStatusNotification(request *core.StatusNotificationRequ
 		conn.assumeMeterStopped()
 	}
 
+	// leaving Preparing status ends the current auth cycle
+	if applied && request.Status != core.ChargePointStatusPreparing {
+		conn.remoteStarted = false
+	}
+
 	if conn.isWaitingForAuth() {
-		if conn.remoteIdTag != "" {
-			// dispatch asynchronously: RemoteStartTransactionRequest issues a
-			// synchronous CS→CP request whose response is read by this same
-			// goroutine, so a blocking call would deadlock the WebSocket read
-			// loop (cf. ocpp_test_handler.go).
+		switch {
+		case conn.remoteIdTag == "":
+			conn.log.DEBUG.Printf("waiting for local authentication")
+
+		case !conn.remoteStarted:
+			// guard against re-firing on repeated Preparing notifications
+			conn.remoteStarted = true
+
+			// dispatch asynchronously
 			go func(idTag string) {
 				if err := conn.RemoteStartTransactionRequest(idTag); err != nil {
 					conn.log.ERROR.Printf("RemoteStartTransaction: %v", err)
 				}
 			}(conn.remoteIdTag)
-		} else {
-			conn.log.DEBUG.Printf("waiting for local authentication")
 		}
 	}
 
diff --git a/charger/ocpp/connector_test.go b/charger/ocpp/connector_test.go
index 3d79678efa..b51fbe6624 100644
--- a/charger/ocpp/connector_test.go
+++ b/charger/ocpp/connector_test.go
@@ -210,6 +210,60 @@ func (suite *connTestSuite) TestOnStatusNotificationClearsStaleTxn() {
 	suite.True(suite.conn.NeedsAuthentication(), "Preparing after Available should require authentication")
 }
 
+// TestOnStatusNotificationRemoteStartGuard ensures RemoteStartTransaction is
+// issued at most once per auth cycle: repeated Preparing notifications must not
+// re-fire it, while a fresh cycle (leaving and re-entering Preparing) re-arms it.
+func (suite *connTestSuite) TestOnStatusNotificationRemoteStartGuard() {
+	suite.conn.remoteIdTag = "evcc"
+
+	// notify sends a status with a strictly increasing timestamp so none is
+	// rejected as stale by timestampValid
+	var offset time.Duration
+	notify := func(status core.ChargePointStatus, code core.ChargePointErrorCode) {
+		offset += time.Second
+		_, err := suite.conn.OnStatusNotification(&core.StatusNotificationRequest{
+			ConnectorId: 1,
+			Status:      status,
+			ErrorCode:   code,
+			Timestamp:   types.NewDateTime(suite.clock.Now().Add(offset)),
+		})
+		suite.NoError(err)
+	}
+	preparing := func() { notify(core.ChargePointStatusPreparing, core.NoError) }
+
+	// first Preparing arms the guard
+	preparing()
+	suite.True(suite.conn.remoteStarted, "guard must be set after first Preparing")
+
+	// repeated Preparing must not re-arm (guard stays set)
+	preparing()
+	suite.True(suite.conn.remoteStarted, "guard must stay set on repeated Preparing")
+
+	// leaving Preparing for any other status ends the auth cycle and resets the guard
+	for _, tc := range []struct {
+		name   string
+		status core.ChargePointStatus
+		code   core.ChargePointErrorCode
+	}{
+		{"Available", core.ChargePointStatusAvailable, core.NoError},
+		{"Charging", core.ChargePointStatusCharging, core.NoError},
+		{"SuspendedEV", core.ChargePointStatusSuspendedEV, core.NoError},
+		{"SuspendedEVSE", core.ChargePointStatusSuspendedEVSE, core.NoError},
+		{"Faulted", core.ChargePointStatusFaulted, core.InternalError},
+	} {
+		// re-arm from Preparing
+		preparing()
+		suite.True(suite.conn.remoteStarted, "guard must be set before transitioning to %s", tc.name)
+
+		notify(tc.status, tc.code)
+		suite.False(suite.conn.remoteStarted, "guard must reset when leaving Preparing to %s", tc.name)
+	}
+
+	// next Preparing re-arms a fresh RemoteStartTransaction
+	preparing()
+	suite.True(suite.conn.remoteStarted, "guard must re-arm on the next auth cycle")
+}
+
 // TestOnStatusNotificationKeepsActiveTxn ensures that an active transaction is
 // not cleared by transient status notifications other than Available.
 func (suite *connTestSuite) TestOnStatusNotificationKeepsActiveTxn() {