Registration for the exam will be on the Joomla.org site approximately 30 days before JoomlaDay Chicago. Signing up on our site puts you on the list to receive the registration link when it becomes available and let's us know how many to plan for to ensure there is enough seating.  When you receive the link to the registration page on Joomla.org, that is where you will pay the $75 fee directly to Joomla/Open Source Matters.  

For more exam FAQs see: https://certification.joomla.org/exams/faqs