/** * @param \Magento\Quote\Model\Quote $quote * @return $this */ protected function _validateCouponCode(\Magento\Quote\Model\Quote $quote) { $code = $quote->getData('coupon_code'); if (strlen($code)) { $addressHasCoupon = false; $addresses = $quote->getAllAddresses(); if (count($addresses) > 0) { foreach ($addresses as $address) { if ($address->hasCouponCode()) { $addressHasCoupon = true; } } if (!$addressHasCoupon) { $quote->setCouponCode(''); } } } return $this; }