TurboTax license code is an 16-character unique code (XXXX-XXXX-XXXX-XXXX) that allow users to activate their TurboTax software and access all the advanced features. When you purchase the TurboTax software, you'll receive a license code that is needed during the installation process. These codes are typically included with the purchase of a new copy of TurboTax software via email in case of purchasing software online.