diff --git a/core/src/main/java/google/registry/beam/invoicing/BillingEvent.java b/core/src/main/java/google/registry/beam/invoicing/BillingEvent.java
index 2b77d2550..4de572c3f 100644
--- a/core/src/main/java/google/registry/beam/invoicing/BillingEvent.java
+++ b/core/src/main/java/google/registry/beam/invoicing/BillingEvent.java
@@ -235,6 +235,7 @@ public abstract class BillingEvent implements Serializable {
                 DATE_TIME_FORMATTER.format(eventTime()),
                 registrarId(),
                 billingId(),
+                poNumber(),
                 tld(),
                 action(),
                 domain(),
diff --git a/core/src/test/java/google/registry/beam/invoicing/BillingEventTest.java b/core/src/test/java/google/registry/beam/invoicing/BillingEventTest.java
index 84dffb5ac..f647dc1c1 100644
--- a/core/src/test/java/google/registry/beam/invoicing/BillingEventTest.java
+++ b/core/src/test/java/google/registry/beam/invoicing/BillingEventTest.java
@@ -133,7 +133,17 @@ public class BillingEventTest {
     BillingEvent event = BillingEvent.parseFromRecord(schemaAndRecord);
     assertThat(event.toCsv())
         .isEqualTo("1,2017-10-24 09:06:03 UTC,2017-01-19 23:59:43 UTC,myRegistrar,"
-            + "12345-CRRHELLO,test,RENEW,example.test,123456,5,USD,20.50,AUTO_RENEW");
+            + "12345-CRRHELLO,,test,RENEW,example.test,123456,5,USD,20.50,AUTO_RENEW");
+  }
+
+  @Test
+  public void testConvertBillingEvent_nonNullPoNumber_toCsv() {
+    GenericRecord record = createRecord();
+    record.put("poNumber", "905610");
+    BillingEvent event = BillingEvent.parseFromRecord(new SchemaAndRecord(record, null));
+    assertThat(event.toCsv())
+        .isEqualTo("1,2017-10-24 09:06:03 UTC,2017-01-19 23:59:43 UTC,myRegistrar,"
+            + "12345-CRRHELLO,905610,test,RENEW,example.test,123456,5,USD,20.50,AUTO_RENEW");
   }
 
   @Test
diff --git a/core/src/test/java/google/registry/beam/invoicing/InvoicingPipelineTest.java b/core/src/test/java/google/registry/beam/invoicing/InvoicingPipelineTest.java
index dcedf4903..d85907df7 100644
--- a/core/src/test/java/google/registry/beam/invoicing/InvoicingPipelineTest.java
+++ b/core/src/test/java/google/registry/beam/invoicing/InvoicingPipelineTest.java
@@ -157,21 +157,21 @@ public class InvoicingPipelineTest {
     return ImmutableMap.of(
         "invoice_details_2017-10_theRegistrar_test.csv",
         ImmutableList.of(
-            "1,2017-10-04 00:00:00 UTC,2017-10-04 00:00:00 UTC,theRegistrar,234,"
+            "1,2017-10-04 00:00:00 UTC,2017-10-04 00:00:00 UTC,theRegistrar,234,,"
                 + "test,RENEW,mydomain2.test,REPO-ID,3,USD,20.50,",
-            "1,2017-10-04 00:00:00 UTC,2017-10-04 00:00:00 UTC,theRegistrar,234,"
+            "1,2017-10-04 00:00:00 UTC,2017-10-04 00:00:00 UTC,theRegistrar,234,,"
                 + "test,RENEW,mydomain.test,REPO-ID,3,USD,20.50,"),
         "invoice_details_2017-10_theRegistrar_hello.csv",
         ImmutableList.of(
-            "1,2017-10-02 00:00:00 UTC,2017-09-29 00:00:00 UTC,theRegistrar,234,"
+            "1,2017-10-02 00:00:00 UTC,2017-09-29 00:00:00 UTC,theRegistrar,234,,"
                 + "hello,CREATE,mydomain3.hello,REPO-ID,5,JPY,70.75,"),
         "invoice_details_2017-10_bestdomains_test.csv",
         ImmutableList.of(
-            "1,2017-10-04 00:00:00 UTC,2017-10-04 00:00:00 UTC,bestdomains,456,"
+            "1,2017-10-04 00:00:00 UTC,2017-10-04 00:00:00 UTC,bestdomains,456,116688,"
                 + "test,RENEW,mydomain4.test,REPO-ID,1,USD,20.50,"),
         "invoice_details_2017-10_anotherRegistrar_test.csv",
         ImmutableList.of(
-            "1,2017-10-04 00:00:00 UTC,2017-10-04 00:00:00 UTC,anotherRegistrar,789,"
+            "1,2017-10-04 00:00:00 UTC,2017-10-04 00:00:00 UTC,anotherRegistrar,789,,"
                 + "test,CREATE,mydomain5.test,REPO-ID,1,USD,0.00,SUNRISE ANCHOR_TENANT"));
   }