diff -u b/includes/common.inc b/includes/common.inc
--- b/includes/common.inc
+++ b/includes/common.inc
@@ -11,7 +11,8 @@
  * modules to provide their own meaningful defaults.
  *
  * @param $config_id
- *   A config id.
+ *   A config id, typically of the form "module-someid", e.g.
+ *   "taxonomy-field_name".
  * @param $defaults_override
  *   Optionally override the defaults.
  */
diff -u b/modules/hs_taxonomy.install b/modules/hs_taxonomy.install
--- b/modules/hs_taxonomy.install
+++ b/modules/hs_taxonomy.install
@@ -92,19 +92,16 @@
 
   foreach (field_info_instances() as $entity_type => $bundles) {
     foreach ($bundles as $bundle => $field_list) {
-      foreach ($field_list as $fieldname => $instance) {
+      foreach ($field_list as $field_name => $instance) {
         if ($instance['widget']['type'] == 'taxonomy_hs') {
-          $field_info = field_info_field($fieldname);
-          $allowed_values = $field_info['settings']['allowed_values'];
-          foreach ($allowed_values as $allowed_value) {
-            $vocabulary_name = $allowed_value['vocabulary'];
-            $old_config_id = "taxonomy-{$vocabulary_name}";
-            $new_config_id = "taxonomy-{$vocabulary_name}-{$fieldname}";
-            $old_config = hierarchical_select_common_config_get($old_config_id);
-            if (!empty($old_config)) {
-              hierarchical_select_common_config_set($new_config_id, $old_config);
-              hierarchical_select_common_config_del($old_config_id);
-            }
+          $field_info = field_info_field($field_name);
+          $allowed_value = $field_info['settings']['allowed_values'][0];
+          $vocabulary_name = $allowed_value['vocabulary'];
+          $old_config_id = "taxonomy-{$vocabulary_name}";
+          $new_config_id = "taxonomy-{$field_name}";
+          $old_config = hierarchical_select_common_config_get($old_config_id);
+          if (!empty($old_config)) {
+            hierarchical_select_common_config_set($new_config_id, $old_config);
           }
         }
       }
diff -u b/modules/hs_taxonomy.module b/modules/hs_taxonomy.module
--- b/modules/hs_taxonomy.module
+++ b/modules/hs_taxonomy.module
@@ -56,7 +56,7 @@
       'root_term'                  => NULL,
       'entity_count_for_node_type' => NULL,
     );
-    $config_id = hs_taxonomy_get_config_id($vocabulary, $form['#field_name']);
+    $config_id = hs_taxonomy_get_config_id($form['#field_name']);
     $defaults = array(
       // Enable the save_lineage setting by default if the multiple parents
       // vocabulary option is enabled.
@@ -109,8 +109,7 @@
  */
 function hs_taxonomy_field_settings_submit(&$form, &$form_state) {
   $field = field_info_field($form['#field_name']);
-  $vocabulary = taxonomy_vocabulary_machine_name_load($field['settings']['allowed_values'][0]['vocabulary']);
-  $config = hierarchical_select_common_config_get(hs_taxonomy_get_config_id($vocabulary, $form['#field_name']));
+  $config = hierarchical_select_common_config_get(hs_taxonomy_get_config_id($form['#field_name']));
 
   if ($config['dropbox']['status'] || $config['save_lineage']) {
     $field = field_info_field($form['#field_name']);
@@ -132,8 +131,7 @@
   if (isset($form['#field']['type']) && $form['#field']['type'] === 'taxonomy_term_reference' && $form['#instance']['widget']['type'] == 'taxonomy_hs') {
     require_once DRUPAL_ROOT . '/' . drupal_get_path('module', 'hierarchical_select') . '/includes/common.inc';
 
-    $vocabulary = taxonomy_vocabulary_machine_name_load($form['#field']['settings']['allowed_values'][0]['vocabulary']);
-    $config = hierarchical_select_common_config_get(hs_taxonomy_get_config_id($vocabulary, $form['#field']['field_name']));
+    $config = hierarchical_select_common_config_get(hs_taxonomy_get_config_id($form['#field']['field_name']));
 
     if ($config['dropbox']['status'] || $config['save_lineage']) {
       $form['field']['cardinality']['#disabled'] = TRUE;
@@ -193,51 +191,13 @@
 }
 
 /**
- * Implements hook_taxonomy_vocabulary_update().
+ * Implements hook_field_delete().
  *
- * This enables us to rename HS configs appropriately when machine names of
- * taxonomy vocabularies change.
- *
- * @param stdClass $vocabulary
- *   The vocabulary that is being updated.
+ * This enables us to delete HS configs when fields are deleted.
  */
-function hs_taxonomy_taxonomy_vocabulary_update(stdClass $vocabulary) {
+function hs_taxonomy_field_delete($entity_type, $entity, $field, $instance, $langcode, &$items) {
   require_once DRUPAL_ROOT . '/' . drupal_get_path('module', 'hierarchical_select') . '/includes/common.inc';
-
-  if (isset($vocabulary->original) && ($vocabulary->machine_name != $vocabulary->original->machine_name)) {
-    // Get all existing config_ids in variable table for this vocabulary.
-    $old_config_ids = hs_taxonomy_get_config_ids($vocabulary->original);
-    // Iterating over existing config_ids, get full config details, then assign it to our new config_id.
-    foreach($old_config_ids as $old_config_id) {
-      $config = hierarchical_select_common_config_get($old_config_id);
-      if (!empty($config)) {
-        $new_config_id = hs_taxonomy_update_config_id($old_config_id, $vocabulary);
-        // Make sure we pass the new config_id through to the variable content as well.
-        $config['config_id'] = $new_config_id;
-        hierarchical_select_common_config_set($new_config_id, $config);
-        // Finally, delete the old config variable.
-        hierarchical_select_common_config_del($old_config_id);
-      }
-    }
-  }
-}
-
-/**
- * Implements hook_taxonomy_vocabulary_delete().
- *
- * This enables us to delete HS configs when vocabularies are deleted.
- *
- * @param stdClass $vocabulary
- *   The vocabulary that is being deleted.
- */
-function hs_taxonomy_taxonomy_vocabulary_delete(stdClass $vocabulary) {
-  require_once DRUPAL_ROOT . '/' . drupal_get_path('module', 'hierarchical_select') . '/includes/common.inc';
-
-  // Get all configs belonging to this vocabulary and delete each one.
-  $config_ids = hs_taxonomy_get_config_ids($vocabulary);
-  foreach($config_ids as $config_id) {
-    hierarchical_select_common_config_del($config_id);
-  }
+  hierarchical_select_common_config_del(hs_taxonomy_get_config_id($field['field_name']));
 }
 
 //----------------------------------------------------------------------------
@@ -302,7 +262,7 @@
     '#default_value' => $tids,
   );
 
-  hierarchical_select_common_config_apply($element, hs_taxonomy_get_config_id($vocabulary, $field['field_name']));
+  hierarchical_select_common_config_apply($element, hs_taxonomy_get_config_id($field['field_name']));
 
   // Append another #process callback that transforms #return_value to the
   // format that Field API/Taxonomy Field expects.
@@ -402,7 +362,7 @@
 
   // Get the config for this field.
   module_load_include('inc', 'hierarchical_select', 'includes/common');
-  $config_id = hs_taxonomy_get_config_id($vocabulary, $field['field_name']);
+  $config_id = hs_taxonomy_get_config_id($field['field_name']);
   $config = hierarchical_select_common_config_get($config_id);
   $config += array(
     'module' => 'hs_taxonomy',
@@ -834,7 +794,7 @@
             $entity_info = entity_get_info($entity_type);
             $machine_name = $field['settings']['allowed_values'][0]['vocabulary'];
             $vocabulary = taxonomy_vocabulary_machine_name_load($machine_name);
-            $config_id = hs_taxonomy_get_config_id($vocabulary, $field_name);
+            $config_id = hs_taxonomy_get_config_id($field_name);
             $config_info[$config_id] = array(
               'config_id'      => $config_id,
               'hierarchy type' => t('Taxonomy'),
@@ -1104,68 +1064,16 @@
 }
 
 /**
- * Returns the configuration ID that would be used for the specified taxonomy
- * vocabulary and field.
+ * Returns the configuration ID that would be used for the specified field.
  *
- * @param stdClass $vocabulary
- *   The vocabulary.
  * @param string $field_name
- *   The field_machine name.
+ *   The field machine name.
  *
  * @return string
- *   The config id for the provided vocabulary and field.
+ *   The config id for the provided field.
  */
-function hs_taxonomy_get_config_id(stdClass $vocabulary, $field_name) {
-  return "taxonomy-{$vocabulary->machine_name}-{$field_name}";
-}
-
-/**
- * Returns all the configuration IDs that have been used for the specified taxonomy
- * vocabulary.
- *
- * @param stdClass $vocabulary
- *   The vocabulary for which config IDs will be returned.
- *
- * @return Array
- *   The config IDs for the provided vocabulary.
- */
-function hs_taxonomy_get_config_ids(stdClass $vocabulary) {
-  // get _all_ hs_config_taxonomy variables from the db for our chosen vocab:
-  $prefix = "hs_config_taxonomy-{$vocabulary->machine_name}";
-  $result = db_select('variable', 'v')
-    ->fields('v', array('name'))
-    ->condition('name', db_like($prefix) . '%', 'LIKE')
-    ->execute()
-    ->fetchCol();
-
-  // now iterate over variable names, remove the hs_config_ prefix and
-  // we are left with the config_id
-  $config_ids = array();
-  foreach($result as $name) {
-    $config_ids[] = preg_replace('/^(hs_config_)(.*)$/', '$2', $name);
-  }
-  return $config_ids;
-}
-
-/**
- * Helper function to return the updated config_id on vocabulary change.
- *
- * @param string $old_config_id
- *    The original config_id string.
- * @param stdClass $vocabulary
- *    The new vocabulary if this has been updated.
- * @return string
- *    The new config id string including the new vocabulary name.
- */
-function hs_taxonomy_update_config_id($old_config_id, $new_vocabulary = null) {
-  $new_config_id = $old_config_id;
-
-  // Replace the vocabulary name component of the config_id with our new vocabulary name
-  if (isset($new_vocabulary) && !empty($new_vocabulary)) {
-    $new_config_id = preg_replace('/^(.*)-(.*)-(.*)$/', "$1-{$new_vocabulary->machine_name}-$3", $new_config_id);
-  }
-
-  return $new_config_id;
+function hs_taxonomy_get_config_id($field_name) {
+  return "taxonomy-{$field_name}";
 }
 
 /**