+function custom_woo_ce_extend_subscription_fields( $fields ) {

+

+    $fields[] = array(

+        'name' => 'paypal_subscriber_id',

+        'label' => __( 'PayPal Subscriber ID', 'woo_ce' ),

+        'hover' => __( 'PayPal Subscriber ID within functions.php', 'woo_ce' )

+    );

+    return $fields;

+

+}

+add_filter( 'woo_ce_subscription_fields', 'custom_woo_ce_extend_subscription_fields' );

+

+function custom_woo_ce_subscription_extend( $subscription, $subscription_id ) {

+

+    $subscription->paypal_subscriber_id = get_post_meta( $subscription_id, 'PayPal Subscriber ID', true );

+    // Legacy Post meta name for PayPal Subscriber ID in WooCommerce Subscriptions

+    // $subscription->paypal_subscriber_id = get_post_meta( $subscription_id, '_paypal_subscription_id', true );    

+    return $subscription;

+

+}

+add_filter( 'woo_ce_subscription', 'custom_woo_ce_subscription_extend', 10, 2 );