Tax extension 2021: How to delay filing your federal and state taxes Updated May 12, 2021; Procrastinator alert: your taxes are due! If you are nowhere near ready as the scary deadline approaches, you may file an extension with the IRS that gives you up to six more months to file your taxes. Filing an extension will spare you from late filing penalties — 5% of the amount of tax you owe for each month or partial month past the deadline. The extension is automatic — you do not have to send any justification or reasoning like “I have 5,000 wadded-up receipts crammed in a shoebox.” The IRS and Treasury Department have extended the 2021 tax filing and payment deadline from April 15th to May 17th, due to the COVID-19 pandemic.