When is the last day you can send in federal income tax forms?

The last day to send in federal income tax forms in the United States is typically April 15th. However, if that date falls on a weekend or a holiday, the deadline may be extended to the next business day. It's also important to note that the IRS may extend this deadline in certain circumstances, such as in response to natural disasters or global events like the COVID-19 pandemic. Always check the IRS website for the most current information.