diff --git a/source/core_mqtt.c b/source/core_mqtt.c
index 0166462c..55afe35d 100644
--- a/source/core_mqtt.c
+++ b/source/core_mqtt.c
@@ -90,6 +90,11 @@
  */
 #define CORE_MQTT_UNSUBSCRIBE_PER_TOPIC_VECTOR_LENGTH    ( 2U )
 
+struct MQTTVec
+{
+    TransportOutVector_t pVector;  /**< Pointer to transport vector. USER SHOULD NOT ACCESS THIS DIRECTLY - IT IS AN INTERNAL DETAIL AND CAN CHANGE. */
+};
+
 /*-----------------------------------------------------------*/
 
 /**
@@ -3726,3 +3731,37 @@ const char * MQTT_Status_strerror( MQTTStatus_t status )
 }
 
 /*-----------------------------------------------------------*/
+
+size_t MQTT_GetBytesInMQTTVec( MQTTVec_t * pVec,
+                               size_t len )
+{
+    size_t memoryRequired = 0;
+    size_t i;
+    TransportOutVector_t * pTransportVec = ( TransportOutVector_t * ) pVec;
+
+    for( i = 0; i < len; i++ )
+    {
+        memoryRequired += pTransportVec[ i ].iov_len;
+    }
+
+    return memoryRequired;
+}
+
+/*-----------------------------------------------------------*/
+
+void MQTT_SerializeMQTTVec( uint8_t * pAllocatedMem,
+                            MQTTVec_t * pVec,
+                            size_t len )
+{
+    TransportOutVector_t * pTransportVec = ( TransportOutVector_t * ) pVec;
+    size_t index = 0;
+    size_t i = 0;
+
+    for( i = 0; i < len; i++ )
+    {
+        memcpy( &pAllocatedMem[ index ], pTransportVec[ i ].iov_base, pTransportVec[ i ].iov_len );
+        index += pTransportVec[ i ].iov_len;
+    }
+}
+
+/*-----------------------------------------------------------*/
diff --git a/source/include/core_mqtt.h b/source/include/core_mqtt.h
index 38069274..eef73276 100644
--- a/source/include/core_mqtt.h
+++ b/source/include/core_mqtt.h
@@ -343,6 +343,12 @@ typedef struct MQTTDeserializedInfo
     MQTTStatus_t deserializationResult; /**< @brief Return code of deserialization. */
 } MQTTDeserializedInfo_t;
 
+/**
+ * @ingroup mqtt_struct_types
+ * @brief An opaque structure provided by the library to the #MQTTStorePacketForRetransmit function when using #MQTTStorePacketForRetransmit.
+ */
+typedef struct MQTTVec MQTTVec_t;
+
 /**
  * @brief Initialize an MQTT context.
  *
@@ -649,7 +655,7 @@ MQTTStatus_t MQTT_CheckConnectStatus( MQTTContext_t * pContext );
  * #MQTTNoDataAvailable if no data available to receive in transport until
  * the @p timeoutMs for CONNACK;
  * #MQTTStatusConnected if the connection is already established
- * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect 
+ * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect
  * before calling any other API
  * MQTTPublishClearAllFailed if on a clean session connection, clearing all the
  * previously copied publishes fails
@@ -744,7 +750,7 @@ MQTTStatus_t MQTT_Connect( MQTTContext_t * pContext,
  * #MQTTBadParameter if invalid parameters are passed;
  * #MQTTSendFailed if transport write failed;
  * #MQTTStatusNotConnected if the connection is not established yet
- * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect 
+ * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect
  * before calling any other API
  * #MQTTSuccess otherwise.
  *
@@ -800,7 +806,7 @@ MQTTStatus_t MQTT_Subscribe( MQTTContext_t * pContext,
  * #MQTTBadParameter if invalid parameters are passed;
  * #MQTTSendFailed if transport write failed;
  * #MQTTStatusNotConnected if the connection is not established yet
- * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect 
+ * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect
  * before calling any other API
  * #MQTTPublishStoreFailed if the user provided callback to copy and store the
  * outgoing publish packet fails
@@ -872,7 +878,7 @@ MQTTStatus_t MQTT_CancelCallback( const MQTTContext_t * pContext,
  * #MQTTBadParameter if invalid parameters are passed;
  * #MQTTSendFailed if transport write failed;
  * #MQTTStatusNotConnected if the connection is not established yet
- * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect 
+ * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect
  * before calling any other API
  * #MQTTSuccess otherwise.
  */
@@ -894,7 +900,7 @@ MQTTStatus_t MQTT_Ping( MQTTContext_t * pContext );
  * #MQTTBadParameter if invalid parameters are passed;
  * #MQTTSendFailed if transport write failed;
  * #MQTTStatusNotConnected if the connection is not established yet
- * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect 
+ * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect
  * before calling any other API
  * #MQTTSuccess otherwise.
  *
@@ -984,7 +990,7 @@ MQTTStatus_t MQTT_Disconnect( MQTTContext_t * pContext );
  * incomplete data; it should be called again (probably after a delay);
  * #MQTTStatusNotConnected if the connection is not established yet and a PING
  * or an ACK is being sent.
- * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect 
+ * #MQTTStatusDisconnectPending if the user is expected to call MQTT_Disconnect
  * before calling any other API
  * #MQTTSuccess on success.
  *
@@ -1240,6 +1246,32 @@ MQTTStatus_t MQTT_GetSubAckStatusCodes( const MQTTPacketInfo_t * pSubackPacket,
 const char * MQTT_Status_strerror( MQTTStatus_t status );
 /* @[declare_mqtt_status_strerror] */
 
+/**
+ * @brief Get the bytes in an array of #MQTTVec_t which can store the whole array as a an MQTT packet when calling MQTT_SerializeMQTTVec( void * pAllocatedMem, MQTTVec_t *pVec, size_t len ) function.
+ *
+ * @param[in] pVec The #MQTTVec_t array.
+ * @param[in] len The length of the #MQTTVec_t array.
+ *
+ * @return The bytes in the provided MQTTVec_t array which can then be used to set aside memory to be used with MQTT_SerializeMQTTVec( void * pAllocatedMem, MQTTVec_t *pVec, size_t len ) function.
+ */
+/* @[declare_mqtt_getbytesinmqttvec] */
+size_t MQTT_GetBytesInMQTTVec( MQTTVec_t * pVec,
+                               size_t len );
+/* @[declare_mqtt_getbytesinmqttvec] */
+
+/**
+ * @brief Serialize the bytes in an array of #MQTTVec_t in the provided \p pAllocatedMem
+ *
+ * @param[in] pAllocatedMem Memory in which to serialize the data in the #MQTTVec_t array. It must be of size provided by MQTT_GetBytesInMQTTVec( MQTTVec_t *pVec, size_t len ).
+ * @param[in] pVec The #MQTTVec_t array.
+ * @param[in] len The length of the #MQTTVec_t array.
+ */
+/* @[declare_mqtt_serializemqttvec] */
+void MQTT_SerializeMQTTVec( uint8_t * pAllocatedMem,
+                            MQTTVec_t * pVec,
+                            size_t len );
+/* @[declare_mqtt_serializemqttvec] */
+
 /* *INDENT-OFF* */
 #ifdef __cplusplus
     }