If you requested an extension for your 2024 tax return, the final deadline to file is October 15, 2025. Missing it can trigger costly penalties. The IRS charges 5% of unpaid taxes per month, up to 25%, for late filing. If you’re over 60 days late, the minimum penalty is $510 or 100% of the tax due, whichever is less. Even if you can’t pay, filing on time reduces your exposure. Interest also compounds daily. Protect your refund, minimize damage—don’t let the deadline pass you by.