To claim a refund, you must file an amended return within 3 years after the date you filed your original return or 2 years after the date you paid the tax. The additional time, provided in Notice 202321, to file an amended return is automatic.This is called "backup withholding. 1. Download Form 1040-X from the IRS website. Fill out a "Change of Address" form at the post office to have all of Decedent's mail forwarded to your address. What are my rights under the Texas Constitution? Tax Rates, Thresholds and Deduction Limits.