BirchBox, online at birchbox.com, save money on hot items when shopping on BirchBox when applying our coupons, promo codes during checkout. Trust us, these coupons are good. Make the best of our BirchBox promo codes to get 20% OFF. All discounts are totally free to use. Birchbox is a New York City-based online monthly subscription service that sends its subscribers a box of four to five selected samples of makeup, or other beauty related products. These products include skincare items, perfumes, organic based products and various other cosmetics.