Hi Denise! You don't need to give any information to the center regarding the Voucher. At present, you don't need anything from it. But you have to make sure that you have your exam scheduled on the right Date with your name(Through phone or whatever way). Why i'm giving stress on scheduling the exam, because there are cases when the center is already having all the terminals(computers used for the exam) booked for some days(by other people). So, if possible shoot them an email(as you were talking about sending email only), writing that you want to give so and so exam on this date, "please register my name". Thats it! If you still have any doubt on this topic, feel free to ask again. We are here to help you..take care and best of luck!!!