Register and activate your account


  • To get started, open
  • Click ‘Sign up here’ to open the registration page
  • Please complete all of the required details in the registration form
  • Make sure that you use a secure password: at least 8 characters with 1 uppercase, 1 lowercase and 1 numeric character.
  • Tick the box to accept the Terms and Conditions.
  • You can also choose to subscribe to receive updates and tips via email.
  • Click ‘Create account’ to continue.
  • Click on the link in the email you have received to activate your account.
  • The activation link in this email is valid for 30 days after you register, so it’s recommended to verify your email address straight away.
  • In the activation page, confirm your server location and click ‘Activate’. Once your account is active, you can log in with your email address and password.
  • Castor has servers available in the Netherlands, the United Kingdom and the United States. You can choose where the data of the studies you create will be stored. 
  • If you are invited by another user to participate in a study, the link in the invitation email should direct to the relevant server location by default

Complete and Continue