diff --git a/CHANGELOG.md b/CHANGELOG.md
index 412c184..1c3d62c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## v3.5.0
+
+- Feat: Add districts with zipcodes, so the REST API can be filtered using a zipcode.
+
 ## v3.4.4
 
 - Refactor: CMB2 'show on' taxonomy field type from 'select_advanced' to 'taxonomy_multicheck'
diff --git a/config/cmb2_metaboxes.php b/config/cmb2_metaboxes.php
index 4873cf9..54acb58 100644
--- a/config/cmb2_metaboxes.php
+++ b/config/cmb2_metaboxes.php
@@ -128,4 +128,37 @@
             ]
         ]
     ],
+	'district_zipcodes' => [
+		'id' => 'openpub_metadata_district_zipcodes',
+		'title' => __('Zipcodes', 'openpub-base'),
+		'object_types' => ['term'],
+		'taxonomies' => ['openpub-district'],
+		'context' => 'normal',
+		'priority' => 'high',
+		'autosave' => true,
+		'fields' => [
+			'zipcodes' => [
+				'heading' => [
+					'type' => 'heading',
+					'name' => __('Zipcodes', 'openpub-base'),
+				],
+				'zipcodes' => [
+					'id' => 'openpub_zipcodes_group',
+					'type' => 'group',
+					'options' => [
+						'add_button' => __('Add new zipcode', 'openpub-base'),
+						'remove_button' => __('Remove zipcode', 'openpub-base'),
+					],
+					'fields' => [
+						[
+							'id' => 'openpub_zipcode',
+							'name' => __('Zipcode', 'openpub-base'),
+							'desc' => __('A zipcode that is part of this district. (Only numbers, no letters)', 'openpub-base'),
+							'type' => 'number',
+						],
+					],
+				],
+			],
+		]
+	]
 ];
diff --git a/config/taxonomies.php b/config/taxonomies.php
index 2c086e2..dc36695 100644
--- a/config/taxonomies.php
+++ b/config/taxonomies.php
@@ -62,4 +62,17 @@
             'plural'   => __('Show on', 'openpub-base')
         ]
     ],
+	'openpub-district' => [
+		'object_types' => ['openpub-item'],
+		'args'         => [
+			'show_in_rest'      => true,
+			'show_admin_column' => true,
+			'capabilities'      => []
+		],
+		'names'        => [
+			'singular' => _x('District', 'Taxonomy definition', 'openpub-base'),
+			'plural'   => _x('Districts', 'Taxonomy definition', 'openpub-base'),
+			'slug'     => 'openpub-kern'
+		]
+	]
 ];
diff --git a/languages/openpub-base-nl_NL.mo b/languages/openpub-base-nl_NL.mo
index 17fe351..eb922ec 100644
Binary files a/languages/openpub-base-nl_NL.mo and b/languages/openpub-base-nl_NL.mo differ
diff --git a/languages/openpub-base-nl_NL.po b/languages/openpub-base-nl_NL.po
index 14bc66b..ad86a6b 100644
--- a/languages/openpub-base-nl_NL.po
+++ b/languages/openpub-base-nl_NL.po
@@ -129,6 +129,26 @@ msgstr "Vrij notitieveld"
 msgid "(the law, authority, local regulations, etc.)"
 msgstr "(wetgeving, bevoegd gezag, uitvoerder, lokale regelgeving)"
 
+#: config/metaboxes.php:133 config/metaboxes.php:143
+msgid "Zipcodes"
+msgstr "Postcodes"
+
+#: config/metaboxes.php:149
+msgid "Add new zipcode"
+msgstr "Voeg nieuwe postcode toe"
+
+#: config/metaboxes.php:150
+msgid "Remove zipcode"
+msgstr "Verwijder postcode"
+
+#: config/metaboxes.php:155
+msgid "Zipcode"
+msgstr "Postcode"
+
+#: config/metaboxes.php:156
+msgid "A zipcode that is part of this district. (Only numbers, no letters)"
+msgstr "Een postcode die bij deze wijk hoort. (Alleen cijfer, geen letters)"
+
 #: config/p2p_connections.php:9
 msgid "Connected item(s)"
 msgstr "Gekoppelde item(s)"
@@ -514,6 +534,16 @@ msgctxt "Taxonomy definition"
 msgid "Usages"
 msgstr "Toepassingen"
 
+#: config/taxonomies.php:73
+msgctxt "Taxonomy definition"
+msgid "District"
+msgstr "Wijk"
+
+#: config/taxonomies.php:73
+msgctxt "Taxonomy definition"
+msgid "Districts"
+msgstr "Wijken"
+
 #: src/Base/Foundation/DependencyChecker.php:62
 msgid "The following plugins are required to use the OpenPub:"
 msgstr "De volgende plugins zijn vereist om gebruik te maken van de OpenPub:"
diff --git a/languages/openpub-base.pot b/languages/openpub-base.pot
index 07186d5..c410fd6 100644
--- a/languages/openpub-base.pot
+++ b/languages/openpub-base.pot
@@ -134,6 +134,26 @@ msgstr "
 msgid "(the law, authority, local regulations, etc.)"
 msgstr ""
 
+#: config/metaboxes.php:133 config/metaboxes.php:143
+msgid "Zipcodes"
+msgstr ""
+
+#: config/metaboxes.php:149
+msgid "Add new zipcode"
+msgstr ""
+
+#: config/metaboxes.php:150
+msgid "Remove zipcode"
+msgstr ""
+
+#: config/metaboxes.php:155
+msgid "Zipcode"
+msgstr ""
+
+#: config/metaboxes.php:156
+msgid "A zipcode that is part of this district. (Only numbers, no letters)"
+msgstr ""
+
 #: config/p2p_connections.php:9
 msgctxt "P2P titel"
 msgid "Connected item(s)"
@@ -422,6 +442,16 @@ msgctxt "Taxonomy definition"
 msgid "Usages"
 msgstr ""
 
+#: config/taxonomies.php:73
+msgctxt "Taxonomy definition"
+msgid "District"
+msgstr ""
+
+#: config/taxonomies.php:73
+msgctxt "Taxonomy definition"
+msgid "Districts"
+msgstr ""
+
 #: src/Base/Foundation/DependencyChecker.php:62
 msgid "The following plugins are required to use the OpenPub:"
 msgstr ""
diff --git a/openpub-base.php b/openpub-base.php
index 5ca75c1..3338239 100644
--- a/openpub-base.php
+++ b/openpub-base.php
@@ -4,7 +4,7 @@
  * Plugin Name:       Yard | OpenPub Base
  * Plugin URI:        https://www.openwebconcept.nl/
  * Description:       Acts as foundation for other OpenPub related content plugins. This plugin implements actions to allow for other plugins to add and/or change Custom Posttypes, Metaboxes, Taxonomies, en Posts 2 posts relations.
- * Version:           3.4.4
+ * Version:           3.5
  * Author:            Yard | Digital Agency
  * Author URI:        https://www.yard.nl/
  * License:           GPL-3.0
diff --git a/src/Base/Foundation/Plugin.php b/src/Base/Foundation/Plugin.php
index 8cca70d..f0cee31 100644
--- a/src/Base/Foundation/Plugin.php
+++ b/src/Base/Foundation/Plugin.php
@@ -19,7 +19,7 @@ class Plugin
      * Version of the plugin.
      * Used for setting versions of enqueue scripts and styles.
      */
-    public const VERSION = '3.4.4';
+    public const VERSION = '3.5';
 
     /**
      * Path to the root of the plugin.
diff --git a/src/Base/Metabox/MetaboxServiceProvider.php b/src/Base/Metabox/MetaboxServiceProvider.php
index e28af25..6ee9b57 100644
--- a/src/Base/Metabox/MetaboxServiceProvider.php
+++ b/src/Base/Metabox/MetaboxServiceProvider.php
@@ -14,6 +14,7 @@ class MetaboxServiceProvider extends ServiceProvider
     public function register()
     {
         $this->plugin->loader->addAction('cmb2_admin_init', $this, 'registerMetaboxes', 10, 0);
+		$this->plugin->loader->addAction('cmb2_save_term_fields', $this, 'saveGroupUnserialized', 10, 1);
         $this->plugin->loader->addAction('admin_notices', new AdminNotice, 'upgradeAdminNotice', 10, 0);
 
         if (class_exists('\WP_CLI')) {
@@ -109,4 +110,24 @@ protected function getShowOnMetabox(array $configMetaboxes): array
     {
         return array_merge($configMetaboxes, $this->plugin->config->get('show_on_metabox'));
     }
+
+	/**
+	 * Save group unserialized so it can be used in the search query.
+	 *
+	 * @param int $termId The current term ID.
+	 */
+	public function saveGroupUnserialized(int $termId): void
+	{
+		delete_term_meta($termId, self::PREFIX . 'openpub_zipcode');
+
+		$zipcodes = get_term_meta($termId, self::PREFIX . 'openpub_zipcodes_group');
+
+		if (! $zipcodes || empty($zipcodes[0])) {
+			return;
+		}
+
+		foreach ( $zipcodes[0] as $zipcode ) {
+			add_term_meta( $termId, self::PREFIX . 'openpub_zipcode', $zipcode['openpub_zipcode'] );
+		}
+	}
 }
diff --git a/src/Base/Repositories/Item.php b/src/Base/Repositories/Item.php
index cfcf5b6..63baf8f 100644
--- a/src/Base/Repositories/Item.php
+++ b/src/Base/Repositories/Item.php
@@ -134,4 +134,22 @@ public static function addAudienceParameters(string $audiences): array
             ]
         ];
     }
+
+	public static function addZipcodeParameter(string $zipcode): array
+	{
+		global $wpdb;
+		$sql = "SELECT term_id FROM {$wpdb->termmeta} WHERE meta_key = '_owc_openpub_zipcode' AND meta_value = %s";
+		$results = $wpdb->get_col($wpdb->prepare($sql, (int)$zipcode));
+
+		return [
+			'tax_query' => [
+				[
+					'taxonomy' => 'openpub-district',
+					'terms' => $results,
+					'field' => 'term_id',
+					'operator' => 'IN'
+				]
+			]
+		];
+	}
 }
diff --git a/src/Base/RestAPI/Controllers/ItemController.php b/src/Base/RestAPI/Controllers/ItemController.php
index aad0828..392e9fc 100644
--- a/src/Base/RestAPI/Controllers/ItemController.php
+++ b/src/Base/RestAPI/Controllers/ItemController.php
@@ -51,6 +51,10 @@ protected function itemQueryBuilder(WP_REST_Request $request = null): Item
             $items->query(Item::addShowOnParameter($request->get_param('source')));
         }
 
+		if ($this->getZipcodeParam($request)) {
+			$items->query(Item::addZipcodeParameter($this->getZipcodeParam($request)));
+		}
+
         if ($this->getAudienceParam($request)) {
             $items->query(Item::addAudienceParameters($this->getAudienceParam($request)));
         }
@@ -211,6 +215,13 @@ protected function getTypeParam(WP_REST_Request $request): string
         return is_string($typeParam) ? $typeParam : '';
     }
 
+	protected function getZipcodeParam(WP_REST_Request $request): string
+	{
+		$typeParam = $request->get_param('zipcode');
+
+		return ! empty($typeParam) && is_string($typeParam) ? $typeParam : '';
+	}
+
     protected function validateBoolean(string $value): bool
     {
         $value = filter_var($value, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);