Ready to score free shipping or get a percentage off your total? Copy the revealed Under Armour coupon code once you've clicked on the deal. When you're ready to checkout, click on the cart icon in the corner of the page. Review your cart and click "Proceed to Checkout" and fill out the necessary information on the next page. In the "Promo Codes" section, click on the "Apply Promo Code" link, and paste your coupon code.