MyDec at MyTax Illinois
The Illinois Department of Revenue (IDOR) updated our processing system and applications, effective September 7, 2021. This upgrade implemented enhancements and will improve the user experience on all applications, including MyDec. All MyDec functionality will remain available, but the application has a new look and will redesign the entry of PTAX-203 information to present the entry screens in a user-friendly manner (ex. display fewer entry boxes on one screen and allow clean navigation backwards and forwards). For more information, see MyDec Helpful Resources under Resources below.