How do I deposit a check? If you’re a smartphone user, avoid a trip to the ATM by easily depositing a check through our mobile banking app. Download the app You can also deposit a check through the Alliant ATM network (at banks where deposits are accepted) Mail Alliant your check for deposit to: U.S. Postal Service Delivery Overnight Delivery Alliant Credit Union Alliant Credit Union P.O. Box 2387 11545 W. Touhy Avenue Des Plaines, IL 60017-2387 Chicago, IL 60666