diff --git a/examples/ESP/main.cpp b/examples/ESP/main.cpp
index 306e700b..3f1611d9 100644
--- a/examples/ESP/main.cpp
+++ b/examples/ESP/main.cpp
@@ -103,35 +103,14 @@ void loop() {
     if (/* RFID chip detected? */ false) {
         String idTag = "0123456789ABCD"; //e.g. idTag = RFID.readIdTag();
 
-        if (!getTransaction()) {
-            //no transaction running or preparing. Begin a new transaction
-            Serial.printf("[main] Begin Transaction with idTag %s\n", idTag.c_str());
-
-            /*
-             * Begin Transaction. The OCPP lib will prepare transaction by checking the Authorization
-             * and listen to the ConnectorPlugged Input. When the Authorization succeeds and an EV
-             * is plugged, the OCPP lib will send the StartTransaction
-             */
-            auto ret = beginTransaction(idTag.c_str());
-
-            if (ret) {
-                Serial.println(F("[main] Transaction initiated. OCPP lib will send a StartTransaction when" \
-                                 "ConnectorPlugged Input becomes true and if the Authorization succeeds"));
-            } else {
-                Serial.println(F("[main] No transaction initiated"));
-            }
-
-        } else {
-            //Transaction already initiated. Check if to stop current Tx by RFID card
-            if (idTag.equals(getTransactionIdTag())) {
-                //card matches -> user can stop Tx
-                Serial.println(F("[main] End transaction by RFID card"));
-
-                endTransaction(idTag.c_str());
-            } else {
-                Serial.println(F("[main] Cannot end transaction by RFID card (different card?)"));
-            }
-        }
+        /*
+         * Begin Transaction. The OCPP lib will prepare transaction by checking the Authorization
+         * and listen to the ConnectorPlugged Input. When the Authorization succeeds and an EV
+         * is plugged, the OCPP lib will send the StartTransaction
+         * 
+         * If transaction already exists, stop by RFID card (if idTag or parentIdTag match)
+         */
+        authorize(idTag.c_str());
     }
 
     //... see MicroOcpp.h for more possibilities
diff --git a/src/MicroOcpp.cpp b/src/MicroOcpp.cpp
index 5dbd3714..efce914e 100644
--- a/src/MicroOcpp.cpp
+++ b/src/MicroOcpp.cpp
@@ -547,7 +547,7 @@ bool endTransaction(const char *idTag, const char *reason, unsigned int connecto
                         }
                         return;
                     }
-                    if (idTagInfo.containsKey("parentIdTag") && !strcmp(idTagInfo["parenIdTag"], tx->getParentIdTag()))
+                    if (idTagInfo.containsKey("parentIdTag") && !strcmp(idTagInfo["parentIdTag"], tx->getParentIdTag()))
                     {
                         endTransaction_authorized(idTag_capture.c_str(), reason_capture.empty() ? (const char*)nullptr : reason_capture.c_str(), connectorId);
                     }
@@ -1397,6 +1397,18 @@ void authorize(const char *idTag, OnReceiveConfListener onConf, OnAbortListener
         MO_DBG_ERR("idTag format violation. Expect c-style string with at most %u characters", IDTAG_LEN_MAX);
         return;
     }
+
+    //check for active transactions
+    for (unsigned int cId = 1; cId < context->getModel().getNumConnectors(); cId++) {
+        if (isTransactionActive(cId)) {
+            //this will check both parentIdTag and idTag
+            if (endTransaction(idTag, "Local", cId)) {
+                MO_DBG_INFO("ended active transaction on connector %d for idTag '%s'", cId, idTag);
+                return;
+            }
+        }
+    }
+
     auto authorize = makeRequest(
         new Authorize(context->getModel(), idTag));
     if (onConf)