diff --git a/giticket/giticket.py b/giticket/giticket.py
index 17f57f6..a765c77 100644
--- a/giticket/giticket.py
+++ b/giticket/giticket.py
@@ -19,7 +19,7 @@ def capitalize(text, capitalize_spaces):
     return text[:capitalize_spaces].upper() + text[capitalize_spaces:] if text else text
 
 
-def update_commit_message(filename, regex, mode, format_string, conventionalcommits=False, capitalize_spaces=0):
+def update_commit_message(filename, regex, mode, format_string, conventionalcommits=False, capitalize_spaces=0, to_trailer=False):
     with io.open(filename, 'r+') as fd:
         contents = fd.readlines()
         commit_msg = contents[0].rstrip('\r\n')
@@ -36,6 +36,18 @@ def update_commit_message(filename, regex, mode, format_string, conventionalcomm
                 tickets = [branch.split(six.text_type('_'))[0]]
             tickets = [t.strip() for t in tickets]
 
+            if to_trailer:
+                trailer = 'Refs: {tickets}\n'.format(tickets=', '.join(tickets))
+                if contents and not contents[-1].endswith('\n'):
+                    contents[-1] += '\n'
+                if not contents or contents[-1].strip() != '':
+                    contents.append('\n')
+                contents.append(trailer)
+                fd.seek(0)
+                fd.writelines(contents)
+                fd.truncate()
+                return
+
             if conventionalcommits and (match := re.match(conventionalcommit_regex, commit_msg)):
                 # If the commit message matches the Conventional Commits spec, we can use the captured groups.
                 type = match.group('type')
@@ -86,6 +98,7 @@ def main(argv=None):
     parser.add_argument('filenames', nargs='+')
     parser.add_argument('--conventionalcommits', action='store_true')
     parser.add_argument('--capitalize', nargs='?', const=1, type=int, default=0)
+    parser.add_argument('--to_trailer', action='store_true')
     parser.add_argument('--regex')
     parser.add_argument('--format', nargs='?')
     parser.add_argument('--mode', nargs='?', const=underscore_split_mode,
@@ -97,7 +110,7 @@ def main(argv=None):
         return 1
     regex = args.regex or r'[A-Z]+-\d+'  # noqa
     format_string = args.format or '{ticket} {commit_msg}' # noqa
-    update_commit_message(args.filenames[0], regex, args.mode, format_string, args.conventionalcommits, args.capitalize)
+    update_commit_message(args.filenames[0], regex, args.mode, format_string, args.conventionalcommits, args.capitalize, args.to_trailer)
 
 
 if __name__ == '__main__':
diff --git a/tests/test_giticket.py b/tests/test_giticket.py
index 9d75268..e3ca259 100644
--- a/tests/test_giticket.py
+++ b/tests/test_giticket.py
@@ -181,6 +181,39 @@ def test_update_commit_message_capitalize_conventionalcommits(mock_branch_name,
     assert path.read() == "feat(JIRA-5678): add new feature\n"
 
 
+@mock.patch(TESTING_MODULE + '.get_branch_name')
+def test_update_commit_message_to_trailer(mock_branch_name, tmpdir):
+    mock_branch_name.return_value = "JIRA-1234_new_feature"
+    path = tmpdir.join('file.txt')
+    path.write("Subject line\n\nBody text.")
+    update_commit_message(six.text_type(path), r'[A-Z]+-\d+',
+                          'regex_match', '{ticket}: {commit_msg}',
+                          to_trailer=True)
+    assert path.read() == "Subject line\n\nBody text.\n\nRefs: JIRA-1234\n"
+
+
+@mock.patch(TESTING_MODULE + '.get_branch_name')
+def test_update_commit_message_to_trailer_subject_only(mock_branch_name, tmpdir):
+    mock_branch_name.return_value = "JIRA-1234_new_feature"
+    path = tmpdir.join('file.txt')
+    path.write("Subject line")
+    update_commit_message(six.text_type(path), r'[A-Z]+-\d+',
+                          'regex_match', '{ticket}: {commit_msg}',
+                          to_trailer=True)
+    assert path.read() == "Subject line\n\nRefs: JIRA-1234\n"
+
+
+@mock.patch(TESTING_MODULE + '.get_branch_name')
+def test_update_commit_message_to_trailer_multiple_tickets(mock_branch_name, tmpdir):
+    mock_branch_name.return_value = "JIRA-1234-JIRA-5678"
+    path = tmpdir.join('file.txt')
+    path.write("Subject line")
+    update_commit_message(six.text_type(path), r'[A-Z]+-\d+',
+                          'regex_match', '{ticket}: {commit_msg}',
+                          to_trailer=True)
+    assert path.read() == "Subject line\n\nRefs: JIRA-1234, JIRA-5678\n"
+
+
 @mock.patch(TESTING_MODULE + '.get_branch_name')
 def test_update_commit_message_capitalize_disabled_by_default(mock_branch_name, tmpdir):
     mock_branch_name.return_value = "JIRA-1234_new_feature"
@@ -246,10 +279,12 @@ def test_main(mock_update_commit_message, mock_argparse):
     mock_args.mode = 'underscore_split'
     mock_args.conventionalcommits = True
     mock_args.capitalize = 0
+    mock_args.to_trailer = False
     mock_argparse.ArgumentParser.return_value.parse_args.return_value = mock_args
     main()
     mock_update_commit_message.assert_called_once_with('foo.txt', r'[A-Z]+-\d+',
                                                        'underscore_split',
                                                        '{ticket} {commit_msg}',
                                                        True,
-                                                       0)
+                                                       0,
+                                                       False)