Your Emerald Card is immediately active when you leave the tax office. If you would like to register your card through the online banking website, go to http://www.hrblock.com/bank/lp/emeraldcard-login.html. You will go to the "My Block" page. You then need to click on Activate Card next to the Emerald Card icon. You will be asked for personal information first and then card information second. You will then go to the "My Block Page. You can also download the mobile app.