Why Is Tax Day Sometimes April 18th?
The annual tax deadline isn't fixed. Learn how the calendar and a little-known Washington, D.C. holiday interact to set the final national filing date.
While April 15th is known as Tax Day, the deadline for filing federal income tax returns is not fixed and often shifts. The rules that govern this deadline reveal a combination of historical precedent, administrative logic, and a key local holiday that has national implications for taxpayers.
The Standard April 15th Deadline
The selection of April 15 as the tax filing deadline is a modern development. Following the 16th Amendment in 1913, which gave Congress the power to levy an income tax, the initial deadline was set as March 1. This was later pushed to March 15 in 1918. For decades, Americans filed their taxes in mid-March with the Bureau of Internal Revenue, the precursor to the Internal Revenue Service (IRS).
A change occurred with the overhaul of the federal tax system in the Internal Revenue Code of 1954. This legislative revision moved the tax filing date from March 15 to April 15, where it has largely remained. The primary reason for this change was to spread out the peak workload for the IRS. It also provided taxpayers an additional month to gather necessary documents, such as Form W-2 from employers and various 1099 forms.
Why the Tax Deadline Moves
The federal tax deadline moves for two primary reasons: weekends and a specific public holiday observed in Washington, D.C. If April 15 falls on a Saturday or a Sunday, the deadline automatically shifts to the next business day, which is the following Monday. This ensures that IRS offices are operational on the final day for filing.
A more unique circumstance involves Emancipation Day, a legal holiday in the District of Columbia that celebrates the freeing of enslaved people in the nation’s capital on April 16, 1862. Because the IRS is a federal agency headquartered in Washington, D.C., it observes all official local holidays. This means a holiday impacting only the District of Columbia can shift the entire nation’s federal tax filing deadline.
The convergence of these two rules is what can push Tax Day to April 18. For example, if April 15 falls on a Saturday, the deadline would normally move to Monday, April 17. However, if April 16 (Emancipation Day) is on a Sunday, the holiday is observed on Monday the 17th. With federal offices closed on that Monday, the tax deadline is pushed one more day to Tuesday, April 18.
Checking Your State’s Deadline
The rules and dates discussed apply specifically to your federal income tax return filed with the IRS. It is important to recognize that state income tax deadlines do not always align with the federal date. While many states with an income tax mirror the federal deadline for simplicity, this is not a universal practice.
Some states have their own unique filing deadlines set by their state legislatures, and these dates can differ from the federal Tax Day. To avoid penalties for late filing or late payment at the state level, you must confirm the specific due date with your state’s department of revenue or equivalent tax agency.