diff --git a/docs/shell.rst b/docs/shell.rst
index c1f37af7..9ffbac38 100644
--- a/docs/shell.rst
+++ b/docs/shell.rst
@@ -650,6 +650,12 @@ create_df
    :module: pySim.ts_102_222
    :func: Ts102222Commands.createdf_parser
 
+resize_ef
+~~~~~~~~~
+.. argparse::
+   :module: pySim.ts_102_222
+   :func: Ts102222Commands.resize_ef_parser
+
 
 ARA-M commands
 --------------
diff --git a/pySim/commands.py b/pySim/commands.py
index fa0458a2..d123e67d 100644
--- a/pySim/commands.py
+++ b/pySim/commands.py
@@ -457,6 +457,10 @@ class SimCardCommands:
         """Execute CREEATE FILE command as per TS 102 222 Section 6.3"""
         return self._tp.send_apdu_checksw(self.cla_byte + 'e00000%02x%s' % (len(payload)//2, payload))
 
+    def resize_file(self, payload: Hexstr):
+        """Execute RESIZE FILE command as per TS 102 222 Section 6.10"""
+        return self._tp.send_apdu_checksw('80d40000%02x%s' % (len(payload)//2, payload))
+
     def delete_file(self, fid):
         """Execute DELETE FILE command as per TS 102 222 Section 6.4"""
         return self._tp.send_apdu_checksw(self.cla_byte + 'e4000002' + fid)
diff --git a/pySim/ts_102_222.py b/pySim/ts_102_222.py
index 4843c77a..f8fdddbd 100644
--- a/pySim/ts_102_222.py
+++ b/pySim/ts_102_222.py
@@ -206,3 +206,25 @@ class Ts102222Commands(CommandSet):
         (data, sw) = self._cmd.card._scc.create_file(b2h(fcp.to_tlv()))
         # the newly-created file is automatically selected but our runtime state knows nothing of it
         self._cmd.lchan.select_file(self._cmd.lchan.selected_file)
+
+    resize_ef_parser = argparse.ArgumentParser()
+    resize_ef_parser.add_argument('NAME', type=str, help='Name or FID of file to be resized')
+    resize_ef_parser._action_groups.pop()
+    resize_ef_required = resize_ef_parser.add_argument_group('required arguments')
+    resize_ef_required.add_argument('--file-size', required=True, type=int, help='Size of file in octets')
+
+    @cmd2.with_argparser(resize_ef_parser)
+    def do_resize_ef(self, opts):
+        """Resize an existing EF below the currently selected DF.  Requires related privileges."""
+        f = self._cmd.lchan.get_file_for_selectable(opts.NAME)
+        ies = [FileIdentifier(decoded=f.fid),
+               FileSize(decoded=opts.file_size)]
+        fcp = FcpTemplate(children=ies)
+        (data, sw) = self._cmd.card._scc.resize_file(b2h(fcp.to_tlv()))
+        # the resized file is automatically selected but our runtime state knows nothing of it
+        self._cmd.lchan.select_file(self._cmd.lchan.selected_file)
+
+    def complete_resize_ef(self, text, line, begidx, endidx) -> List[str]:
+        """Command Line tab completion for RESIZE EF"""
+        index_dict = {1: self._cmd.lchan.selected_file.get_selectable_names()}
+        return self._cmd.index_based_complete(text, line, begidx, endidx, index_dict=index_dict)