Specific instructions for enabling 2FA are subject to change without notice. Please check with each website or app for the most up-to-date information on this feature. Two-step verification is an optional but highly recommended security feature that adds an extra layer of protection to your Dropbox account. Once enabled, Dropbox will require a six-digit security code in addition to your password whenever you sign in to Dropbox or link a new computer, phone, or tablet. Before enabling two-step verification, you'll receive a special 16-digit backup code. It is very important that you write this key down and store it somewhere safe. If you ever lose your phone, or can't receive or generate a security code, you'll need this backup code for emergency access to your Dropbox.