diff --git a/includes/api/class-wc-rest-coupons-controller.php b/includes/api/class-wc-rest-coupons-controller.php
index ae86cc07824..245f398b6be 100644
--- a/includes/api/class-wc-rest-coupons-controller.php
+++ b/includes/api/class-wc-rest-coupons-controller.php
@@ -119,7 +119,7 @@ class WC_REST_Coupons_Controller extends WC_REST_Coupons_V1_Controller {
 					case 'meta_data' :
 						if ( is_array( $value ) ) {
 							foreach ( $value as $meta ) {
-								$coupon->update_meta_data( $meta['key'], $meta['value'], $meta['id'] );
+								$coupon->update_meta_data( $meta['key'], $meta['value'], isset( $meta['id'] ) ? $meta['id'] : '' );
 							}
 						}
 						break;
diff --git a/includes/api/class-wc-rest-customers-controller.php b/includes/api/class-wc-rest-customers-controller.php
index e8d4cbbf930..7fbe1507bbd 100644
--- a/includes/api/class-wc-rest-customers-controller.php
+++ b/includes/api/class-wc-rest-customers-controller.php
@@ -85,7 +85,7 @@ class WC_REST_Customers_Controller extends WC_REST_Customers_V1_Controller {
 		if ( isset( $request['meta_data'] ) ) {
 			if ( is_array( $request['meta_data'] ) ) {
 				foreach ( $request['meta_data'] as $meta ) {
-					$customer->update_meta_data( $meta['key'], $meta['value'], $meta['id'] );
+					$customer->update_meta_data( $meta['key'], $meta['value'], isset( $meta['id'] ) ? $meta['id'] : '' );
 				}
 			}
 		}
diff --git a/includes/api/class-wc-rest-orders-controller.php b/includes/api/class-wc-rest-orders-controller.php
index 727a381f3d2..fa1c205660c 100644
--- a/includes/api/class-wc-rest-orders-controller.php
+++ b/includes/api/class-wc-rest-orders-controller.php
@@ -189,7 +189,7 @@ class WC_REST_Orders_Controller extends WC_REST_Orders_V1_Controller {
 					case 'meta_data' :
 						if ( is_array( $value ) ) {
 							foreach ( $value as $meta ) {
-								$order->update_meta_data( $meta['key'], $meta['value'], $meta['id'] );
+								$order->update_meta_data( $meta['key'], $meta['value'], isset( $meta['id'] ) ? $meta['id'] : '' );
 							}
 						}
 						break;
diff --git a/includes/api/class-wc-rest-products-controller.php b/includes/api/class-wc-rest-products-controller.php
index f4771bd4413..4a6e489412e 100644
--- a/includes/api/class-wc-rest-products-controller.php
+++ b/includes/api/class-wc-rest-products-controller.php
@@ -241,8 +241,7 @@ class WC_REST_Products_Controller extends WC_REST_Products_V1_Controller {
 		// Allow set meta_data.
 		if ( is_array( $request['meta_data'] ) ) {
 			foreach ( $request['meta_data'] as $meta ) {
-				$meta_id = isset( $meta['id'] ) ? $meta['id'] : '';
-				$product->update_meta_data( $meta['key'], $meta['value'], $meta_id );
+				$product->update_meta_data( $meta['key'], $meta['value'], isset( $meta['id'] ) ? $meta['id'] : '' );
 			}
 		}