The last day to file individual federal income taxes for the 2024 tax year (filed in 2025) in the United States is April 15, 2025. If more time is needed, taxpayers can file Form 4868 to request an extension, which moves the filing deadline to October 15, 2025. Special circumstances or additional extensions may allow filing as late as December 15, 2025, but the initial and critical deadline remains April 15, 2025, for filing and payment of any taxes owed to avoid penalties and interest.

Key deadlines for the 2024 tax year in the US:

• Regular Deadline: April 15, 2025
• Extension Deadline (with Form 4868): October 15, 2025
• Final extension (special cases): December 15, 2025

For taxpayers abroad, there is typically an automatic extension to June 15, 2026, for the 2025 tax year if living abroad on April 15, 2026, but this applies for the next year's return.

Therefore, the typical last day to file taxes for most individual taxpayers is April 15 of the year following the tax year, with an option to extend the filing deadline to October 15.