IRS filing deadlines 2027: due dates, extensions and special cases

The 2027 filing calendar at a glance

The dates below assume a December 31 year-end and no special relief. March 15, April 15 and June 15, 2027 fall on weekdays. Filing extensions appear in a separate column because a postponed filing deadline and a postponed payment deadline are different events. A firm’s review dates normally precede both.

The source check on October 10, 2026 found the final Publication 509 for 2026, a draft of Publication 509 for 2027, and the current return instructions listed below. The draft is not final. These planning dates apply general rules; recheck the final return-year instructions, IRS notices and taxpayer circumstances before assigning a binding deadline.

Scroll the table if needed.

Which deadline applies to a business return?

Domestic partnerships generally file Form 1065 by the fifteenth day of the third month following the year-end. S corporations follow the same general month rule for Form 1120-S. A calendar-year engagement therefore points to March, while a September 30 year-end points to December. The tax year needs to be recorded before the date is calculated.

Form 1120 generally uses the fifteenth day of the fourth month after year-end. Do not infer that a foreign shareholder changes a domestic corporation’s return to Form 1120-F. That form concerns foreign corporations; its April or June calendar-year date depends in particular on a US office or place of business. These distinctions come from the IRS return instructions, not from the marketing description of the engagement.

A foreign-owned US disregarded entity can have Form 5472 obligations with a pro forma Form 1120. The filing package and submission method deserve their own checklist. Recording “1120” in a calendar without noting that it is pro forma can send the preparer down the wrong workflow.

Individual returns: residency and income change the answer

For a regular calendar-year Form 1040, April 15 is the general reference date. The nationality of the client alone does not determine the return or its deadline. Residency status, the year covered and any applicable relief are questions for the professional reviewing the file.

For Form 1040-NR, the IRS instructions distinguish an employee who received wages subject to US income tax withholding from a filer who did not. The latter generally uses the fifteenth day of the sixth month. A firm should record the reason for the June date, rather than label every nonresident engagement “June 15”.

Certain US citizens and resident aliens abroad qualify for an automatic two-month filing extension under Publication 54. That is not a universal expatriate rule. A further filing extension generally leads to October 15, rather than December 15 merely because the initial overseas deadline was June. Interest on unpaid tax can still run from the regular April date.

An extension buys filing time; payment stays on its own track

Form 7004 is used for specified business returns; Form 4868 is used for individual income tax returns. The appropriate request needs to be made under the applicable instructions by the relevant original deadline. A preparer also checks whether the extension was accepted and retains the confirmation in the engagement file.

The typical six-month filing extension in the calendar above does not erase a payment obligation. A useful register therefore holds the original filing date, extended filing date, payment date, extension request and evidence separately. A “completed” extension task should never silently close an unpaid-tax task.

Scroll the table if needed.

Estimated payments have a different annual rhythm

For ordinary calendar-year individual estimated tax payments, the general federal dates fall in April, June, September and January of the following year. Calendar-year corporate installments instead use April, June, September and December. The names Q1 to Q4 do not mean four identical three-month intervals.

The January 15, 2028 individual date falls on Saturday, followed by the January 17 Martin Luther King Jr. federal holiday. Applying the general next-business-day rule yields Tuesday, January 18, 2028. This projection needs to be checked again against the applicable IRS instructions and any special relief before it is used for a client. The estimated tax guide explains the payment bases and exceptions.

Weekends, fiscal years and relief notices

An IRS deadline that falls on a Saturday, Sunday or applicable legal holiday generally moves to the next business day. A calendar application’s local holiday setting is not sufficient evidence of the federal tax rule. State calendars and payment portals also need their own checks.

A fictitious partnership ending its tax year September 30, 2026 generally files December 15, 2026. A C corporation with the same year-end generally files January 15, 2027. These examples demonstrate the month calculation; they are not a template for June 30 transitions, short years, dissolved entities or other special cases.

Disaster relief is taxpayer- and location-specific. The IRS notice establishes the covered periods, acts and eligibility. Keep the notice beside the revised deadline and check whether the relevant state has adopted separate relief. The calendar download is a starting point, not a live feed of subsequent notices.

Turn reference dates into a working season

Tax Workflow organizes return statuses, owners, checklists and the recorded steps leading to e-file. The firm prepares and files the return in its tax software. Use the calendar template to prepare the season, then review how a sample engagement is followed in the product. Neither an editorial calendar nor a displayed status substitutes for filing evidence.

1. 01

   Qualify the engagement

   Confirm entity, tax year, return, residency and relevant jurisdictions. Record who reviewed the deadline.

2. 02

   Separate the milestones

   Keep receipt of documents, preparation, signature, payment, extension and filing evidence visible as different tasks.

3. 03

   Review the exceptions

   Check special instructions and relief notices before using a portfolio-wide date.

4. 04

   Keep the calendar and file aligned

   When a date changes, record the reason and update the owner’s plan and supporting documents together.

Common questions