The Transaction Authentication Value (TAV) is used as an extra fraud protection measure, sometimes requested when making purchases over the Internet. Online merchants may request TAV as an extra step to ensure that you are the actual owner of the account.

Choose a 3-digit numerical code that only you know. Ensure this code is hard for any other person to guess. You may change your TAV as often as you'd like - you may even change it prior to every online transaction you make.