To amend a Utah state tax return, an individual should use Form TC-40A, the Amended Utah Individual Income Tax Return. This form is specifically designed for those who need to correct their previously filed income tax return. To begin the amendment process, you will need to provide details from the original return, indicate the changes you are making, and provide any additional information or documentation that supports those changes. It is important to note that amendments must generally be filed within three years from the original due date of the return, including extensions. Once you have completed the form, be sure to send it to the address indicated in the instructions. For the most accurate and updated information on this process, individuals are encouraged to refer to the Utah State Tax Commission's official website, where they can find the necessary forms and additional details.