diff --git a/plugins/existing_terms.inc b/plugins/existing_terms.inc
new file mode 100644
index 0000000..95c54e1
--- /dev/null
+++ b/plugins/existing_terms.inc
@@ -0,0 +1,51 @@
+<?php
+
+/**
+ * @file
+ * Taxonomy filter only allowing terms 
+ */
+
+$plugin = array(
+  'form' => 'feeds_tamper_existing_terms_form',
+  'callback' => 'feeds_tamper_existing_terms_callback',
+  'name' => 'Only existing terms',
+  'category' => 'Taxonomy',
+  'single' => 'direct',
+  'multi' => 'direct',
+);
+
+function feeds_tamper_existing_terms_form($importer, $element_key, $settings) {
+  $form = array();
+  $options = array();
+  foreach (taxonomy_vocabulary_get_names() as $machine_name => $data) {
+    $options[$machine_name] = $data->name;
+  }
+  $form['vocabulary'] = array(
+    '#type' => 'select',
+    '#title' => t('Vocabulary whose terms are allowed'),
+    '#options' => $options,
+    '#required' => TRUE,
+    '#default_value' => isset($settings['vocabulary']) ? $settings['vocabulary'] : '',
+  );
+  return $form;
+}
+
+function feeds_tamper_existing_terms_callback($result, $item_key, $element_key, &$field, $settings) {
+  static $allowed = array();
+  if (!isset($allowed[$settings['vocabulary']])) {
+    // fetch all term names in the configured vocabulary
+    $allowed[$settings['vocabulary']] = db_query(
+      'SELECT td.name 
+        FROM {taxonomy_vocabulary} AS v 
+        INNER JOIN {taxonomy_term_data} AS td ON td.vid = v.vid 
+        WHERE v.machine_name = :machine_name
+        GROUP BY td.name;',
+      array(':machine_name' => $settings['vocabulary'])
+    )->fetchCol('name');
+  }
+  if (is_array($field)) {
+    $field = array_intersect($field, $allowed[$settings['vocabulary']]);
+  } else {
+    $field = in_array($field, $allowed[$settings['vocabulary']]) ? $field : '';
+  }
+}