Вся магия - Создать купон программно
Или
$coupon_code = 'UNIQUECODE'; // Code
$amount = '10'; // Amount
$discount_type = 'fixed_cart'; // Type: fixed_cart, percent, fixed_product, percent_product
$wp_prefix = 'wp_';
$post_author = 1; // post author ID
$sql = "INSERT INTO `{$wp_prefix}posts`
(`post_title`, `post_content`, `post_status`, `post_author`, `post_type`)
VALUES
({$coupon_code}, '', 'publish', {$post_author}, 'shop_coupon')";
$coupon_id = $last_inser_id;
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'discount_type', {$discount_type})";
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'coupon_amount', {$amount})";
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'individual_use', 'no')";
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'product_ids', '')";
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'exclude_product_ids', '')";
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'usage_limit', '')";
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'expiry_date', '')";
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'apply_before_tax', 'yes')";
$sql = "INSERT INTO `{$wp_prefix}postmeta`
(`post_id`, `meta_key`, `meta_value`)
VALUES
({$coupon_id}, 'free_shipping', 'no')";