Yes, you will need a product key to activate TurboTax 2020 after downloading it from the official website, installturbotax.com 2020. The product key is typically included in your purchase confirmation email or found on the packaging if you bought a physical copy. Once you launch the software, it will prompt you to enter the product key to complete the activation process and start using TurboTax. Make sure to keep your key handy to avoid any issues during activation.