You can apply for an ATAS certificate up to 6 months in advance of your course start date. You must have received a conditional offer of admission before you apply. Further, you should also check that your Statement of Research has been made available for you to view via your Self-Service. If you cannot view your summary of research then please contact the Department directly before you apply. A valid ATAS certificate is required before you make your Tier 4 visa application.