diff --git a/nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverter.java b/nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverter.java
index de44ea7d6..8f5eafec2 100644
--- a/nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverter.java
+++ b/nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverter.java
@@ -18,6 +18,7 @@ public ListWorkflowInstanceResponse convert(WorkflowInstance instance, QueryWork
     resp.id = instance.id;
     resp.type = instance.type;
     resp.businessKey = instance.businessKey;
+    resp.externalId = instance.externalId;
     resp.state = instance.state;
     resp.stateText = instance.stateText;
     resp.nextActivation = instance.nextActivation;
diff --git a/nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/msg/ListWorkflowInstanceResponse.java b/nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/msg/ListWorkflowInstanceResponse.java
index e277ed232..e18783760 100644
--- a/nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/msg/ListWorkflowInstanceResponse.java
+++ b/nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/msg/ListWorkflowInstanceResponse.java
@@ -22,6 +22,9 @@ public class ListWorkflowInstanceResponse {
   @ApiModelProperty(value = "Main business key or identifier for the started workflow instance", required=false)
   public String businessKey;
 
+  @ApiModelProperty(value = "Unique external identifier under workflow type. Generated by nflow if not given.", required=true)
+  public String externalId;
+
   @ApiModelProperty(value = "State of the workflow instance", required=true)
   public String state;
 
diff --git a/nflow-rest-api/src/test/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverterTest.java b/nflow-rest-api/src/test/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverterTest.java
index 18c842db5..b205206de 100644
--- a/nflow-rest-api/src/test/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverterTest.java
+++ b/nflow-rest-api/src/test/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverterTest.java
@@ -17,7 +17,6 @@
 import com.nitorcreations.nflow.engine.workflow.instance.QueryWorkflowInstances;
 import com.nitorcreations.nflow.engine.workflow.instance.WorkflowInstance;
 import com.nitorcreations.nflow.engine.workflow.instance.WorkflowInstanceAction;
-import com.nitorcreations.nflow.rest.v1.converter.ListWorkflowInstanceConverter;
 import com.nitorcreations.nflow.rest.v1.msg.Action;
 import com.nitorcreations.nflow.rest.v1.msg.ListWorkflowInstanceResponse;
 
@@ -36,12 +35,14 @@ public void convertWithActionsWorks() {
     WorkflowInstanceAction a = new WorkflowInstanceAction.Builder().setState("oState").setStateText("oState desc").
         setRetryNo(1).setExecutionStart(now().minusDays(1)).setExecutionEnd(now().plusDays(1)).build();
     WorkflowInstance i = new WorkflowInstance.Builder().setId(1).setType("dummy").setBusinessKey("businessKey").
-        setState("cState").setStateText("cState desc").setNextActivation(now()).setActions(Arrays.asList(a)).build();
+        setExternalId("externalId").setState("cState").setStateText("cState desc").setNextActivation(now()).
+        setActions(Arrays.asList(a)).build();
 
     ListWorkflowInstanceResponse resp = converter.convert(i, new QueryWorkflowInstances.Builder().setIncludeActions(true).build());
     assertThat(resp.id, is(i.id));
     assertThat(resp.type, is(i.type));
     assertThat(resp.businessKey, is(i.businessKey));
+    assertThat(resp.externalId, is(i.externalId));
     assertThat(resp.state, is(i.state));
     assertThat(resp.stateText, is(i.stateText));
     assertThat(resp.nextActivation, is(i.nextActivation));
@@ -54,12 +55,14 @@ public void convertWithoutActionsWorks() {
     WorkflowInstanceAction a = new WorkflowInstanceAction.Builder().setState("oState").setStateText("oState desc").
         setRetryNo(1).setExecutionStart(now().minusDays(1)).setExecutionEnd(now().plusDays(1)).build();
     WorkflowInstance i = new WorkflowInstance.Builder().setId(1).setType("dummy").setBusinessKey("businessKey").
-        setState("cState").setStateText("cState desc").setNextActivation(now()).setActions(Arrays.asList(a)).build();
+        setExternalId("externalId").setState("cState").setStateText("cState desc").setNextActivation(now())
+        .setActions(Arrays.asList(a)).build();
 
     ListWorkflowInstanceResponse resp = converter.convert(i, new QueryWorkflowInstances.Builder().build());
     assertThat(resp.id, is(i.id));
     assertThat(resp.type, is(i.type));
     assertThat(resp.businessKey, is(i.businessKey));
+    assertThat(resp.externalId, is(i.externalId));
     assertThat(resp.state, is(i.state));
     assertThat(resp.stateText, is(i.stateText));
     assertThat(resp.nextActivation, is(i.nextActivation));