How do I join? Joining Alliant is easy. You can complete our secure online membership application. Alternatively, you can download and mail in your completed member enrollment application (PDF) to: U.S Postal Service Delivery Overnight Service Alliant Credit Union Alliant Credit Union Attn. Account Services Attn. Account Services P.O. Box 66945 11545 W. Touhy Ave. Chicago, IL 60666-0945 Chicago, IL 60666 Note: If you have a credit freeze, please temporarily release it in order to apply. If you are opening an account for a minor or have a Fraud Victim Alert with a credit bureau, you will have to mail us a member enrollment application (PDF). For more information, please contact us anytime at (800) 328-1935 (24/7).
