diff --git a/includes/api/class-wc-rest-shipping-zone-locations-controller.php b/includes/api/class-wc-rest-shipping-zone-locations-controller.php
index 07c965456d0..71c867bc670 100644
--- a/includes/api/class-wc-rest-shipping-zone-locations-controller.php
+++ b/includes/api/class-wc-rest-shipping-zone-locations-controller.php
@@ -86,6 +86,10 @@ class WC_REST_Shipping_Zone_Locations_Controller extends WC_REST_Shipping_Zones_
 			return $zone;
 		}
 
+		if ( 0 === $zone->get_id() ) {
+			return new WP_Error( "woocommerce_rest_shipping_zone_locations_invalid_zone", __( 'The "rest of the world" zone cannot be updated.', 'woocommerce' ), array( 'status' => 403 ) );
+		}
+
 		$raw_locations = $request->get_json_params();
 		$locations     = array();
 
diff --git a/includes/api/class-wc-rest-shipping-zones-controller.php b/includes/api/class-wc-rest-shipping-zones-controller.php
index fe85cfcdbaa..e77e184018c 100644
--- a/includes/api/class-wc-rest-shipping-zones-controller.php
+++ b/includes/api/class-wc-rest-shipping-zones-controller.php
@@ -166,6 +166,10 @@ class WC_REST_Shipping_Zones_Controller extends WC_REST_Shipping_Zones_Controlle
 			return $zone;
 		}
 
+		if ( 0 === $zone->get_id() ) {
+			return new WP_Error( "woocommerce_rest_shipping_zone_invalid_zone", __( 'The "rest of the world" zone cannot be updated.', 'woocommerce' ), array( 'status' => 403 ) );
+		}
+
 		$zone_changed = false;
 
 		if ( ! is_null( $request->get_param( 'name' ) ) ) {
diff --git a/includes/class-wc-shipping-zone.php b/includes/class-wc-shipping-zone.php
index bcc406770e1..2154e61fdc4 100644
--- a/includes/class-wc-shipping-zone.php
+++ b/includes/class-wc-shipping-zone.php
@@ -229,7 +229,9 @@ class WC_Shipping_Zone extends WC_Legacy_Shipping_Zone {
 	 * @param array
 	 */
 	public function set_zone_locations( $locations ) {
-		$this->set_prop( 'zone_locations', $locations );
+		if ( 0 !== $this->get_id() ) {
+			$this->set_prop( 'zone_locations', $locations );
+		}
 	}
 
 	/*
@@ -332,7 +334,7 @@ class WC_Shipping_Zone extends WC_Legacy_Shipping_Zone {
 	 * @param string $type state or postcode
 	 */
 	public function add_location( $code, $type ) {
-		if ( $this->is_valid_location_type( $type ) ) {
+		if ( 0 !== $this->get_id() && $this->is_valid_location_type( $type ) ) {
 			if ( 'postcode' === $type ) {
 				$code = trim( strtoupper( str_replace( chr( 226 ) . chr( 128 ) . chr( 166 ), '...', $code ) ) ); // No normalization - postcodes are matched against both normal and formatted versions to support wildcards.
 			}