If you can't file your taxes by the April 18 deadline, you can instead request a tax-filing extension that extends your paperwork deadline by six months. For C corporations and sole proprietors, your new tax deadline will be October 16, 2023 with the extension. Bear in mind that an extension only extends the time period for filing paperwork. Your tax payments are still due no later than the 18th, though you can work with the IRS to build a payment plan if you can't pay taxes immediately.