Gap and Old Navy: 20% off Your PurchaseDecember 10, 2010 by Mitchell Wischmann This post may contain a link to an affiliate. See my disclosure policy for more information. Old Navy* and Gap are both offering up 20% off any purchase! Here are the coupon codes:Old Navy: Use coupon code ONGIFT20 today onlyGap: Use coupon code GAP20 through 12/12/10**Don’t forget to go through ShopAtHome! You’ll earn 8% cash back on your Old Navy and Gap purchases.*Excludes everyday steals and sweaters.