diff --git a/ach/builder.py b/ach/builder.py
index 1a3c70f..1b9bf0b 100644
--- a/ach/builder.py
+++ b/ach/builder.py
@@ -93,6 +93,7 @@ def add_batch(self, std_ent_cls_code, batch_entries=None,
             entry.ind_name = record['name'].upper()[:22]
             entry.trace_num = self.settings['immediate_dest'][:8] \
                 + entry.validate_numeric_field(entry_counter, 7)
+            entry.id_number = record.get('id_number', '')[:15]
 
             entries.append((entry, record.get('addenda', [])))
             entry_counter += 1