Telephone lines are open Monday-Friday in each region, except on local national holidays. If you have questions about the GMAT® exam, please contact GMAT® Customer Service in your region: You may register for the test online, by phone, by mail, or by fax. You may incur taxes to schedule an exam in certain countries. Fill out the registration form included in our information package, or click here for a version you can print out and fax. Include the credit card payment details and fax the completed form to 1-800-955-9950.