The following individuals must file a Utah individual income tax return:
If you must file a Utah return, first complete a federal return, even if you don't have to file with the IRS. You need the federal return information to complete the Utah return.
You may be exempt from Utah individual income tax if your federal adjusted gross income is less than the sum of your federal standard deduction and federal personal exemptions amount for the taxable year. This page gives for more information.
Utah nonresidents whose only source of Utah income was from being a member of a pass-through entity (entities taxed as partnerships, S-corporations, or trusts), are not required to file a Utah return if the pass-through entity withheld Utah taxes on the income. They may file if they would be due a refund of all or part of the taxes withheld. If taxes have not been withheld on the Utah sourced income passed through to you, you must file a Utah return.
More information about Utah's statute of limitations for applying for a refund is available here.