We'll create fresh WordPress site with Coupon Restriction For Backorders on WooCommerce installed. You have 20 minutes to test the plugin after that site we'll be deleted.
This is a simple plugin used to apply coupon restriction when the backorder item is in the cart. This coupon restriction will only apply if the product set to backorder and stock is less than 0.
Usage is easy – there is no configuration just added two fields to the Usage restriction tab under Coupons menu.
Two fields are Backorder Restriction and Backorder Restriction Message. You need to allow Backorder Restriction in order to active this feature. You can add your custom restriction message in the Backorder Restriction Message input box which shows on the cart page or checkout page.
Note: Coupon restriction will not apply if the cart has other instock or outofstock products along with the backorder products. It will only apply if the all products are backorder in the cart.