Estimated tax due dates: the full calendar for individuals, corporations, and fiscal years

If you are trying to work out when your next estimated tax payment is due, the answer depends on whether you are paying personally or through a company, and on whether that company uses the calendar year.

Individuals pay on April 15, June 15, September 15, and January 15 of the following year. Corporations do not use those dates at all. They pay on the fifteenth day of the fourth, sixth, ninth, and twelfth months of their own fiscal year, which for a calendar-year company means the last payment falls in December rather than the following January.

Both schedules shift when a date lands on a weekend or a federal holiday. Here is the full calendar, the periods sitting behind each date, and the circumstances that change them.

The individual dates and the periods behind them

The four payment dates cover unequal stretches of the year, which is the detail that causes most missed payments.

April 15 covers income earned from January 1 through March 31.

June 15 covers April 1 through May 31. Two months, not three.

September 15 covers June 1 through August 31.

January 15 of the following year covers September 1 through December 31. Four months.

Because the second period is short, the June payment arrives only two months after the April one. Anyone who sets a recurring reminder on a true three-month cycle will be two weeks late on it, every year. Diarize the four dates individually rather than as a quarterly repeat.

A payment is credited to the period in which you make it. Paying extra in September does not repair a shortfall from April, which is why the calendar matters more here than it does for an annual filing.

Corporations follow their fiscal year, not the calendar

Corporate installments are tied to the fiscal year, due on the fifteenth day of the fourth, sixth, ninth, and twelfth months.

For a calendar-year corporation that produces April 15, June 15, September 15, and December 15. The first three coincide with the individual dates by arithmetic rather than by rule, and the fourth does not exist for individuals at all. A calendar-year company's final installment is due sixteen days before year end.

For a corporation with a June 30 year end, the same rule produces October 15, December 15, March 15, and June 15. Nothing about the calendar year applies.

This is the point most guidance gets wrong, including sources that state corporations use the same dates as individuals. They do not, and a fiscal-year company following the individual calendar will be late on every installment.

The January payment can be skipped

An individual can avoid the January 15 payment entirely by filing the tax return and paying the full balance due by January 31.

It is a real option rather than a technicality. If your figures are settled early and you would rather deal with the year once, filing in January closes it out. If you cannot file that quickly, make the January 15 payment as normal.

The equivalent does not exist for corporations, whose final installment is due in the twelfth month of the fiscal year regardless of when the return is filed.

Weekends, holidays, and disaster postponements

When a due date falls on a Saturday, Sunday, or legal holiday, the payment is due on the next business day. This shifts dates more often than people expect, and April 15 is affected by a District of Columbia holiday in some years even when it falls midweek.

The IRS also postpones deadlines for taxpayers in federally declared disaster areas, and those postponements commonly cover estimated tax payments as well as filings. Relief is granted by area and announced case by case, so the applicable date depends on where the taxpayer is located rather than where the business is incorporated.

Neither adjustment is something to assume. Check the date for the specific year rather than working from a figure in older guidance, which is how stale calendars propagate.

Farmers and fishermen file on a different clock

Anyone deriving at least two-thirds of their annual gross income from farming or fishing is outside the four-payment schedule.

They have two options. Make a single estimated payment by January 15, or skip estimated payments entirely and file the return with the full balance paid by March 1. The two-thirds test is measured on gross income, and it has to be met for the relevant year rather than assumed from prior years.

State dates do not match the federal ones

Assuming the state schedule mirrors the federal one is a common and expensive error.

California is the clearest case. It uses three installments rather than four, taking 30% of the annual amount in April, 40% in June, nothing in September, and 30% in January. A taxpayer making four equal California payments on the federal rhythm is underpaid from June onward, even with a perfect federal record.

Other states vary in both dates and thresholds, and several require payments from companies that owe nothing federally.

Inkle files quarterly and annual estimated tax federally and handles state tax filings including California, so a company's state installments are scheduled off the same figures as the federal ones instead of being tracked separately. It is worth asking any provider which states they cover, since state estimated tax is frequently left with the client.

Missing one date is not the same as missing the year

The underpayment charge accrues per period, at a rate tied to the federal short-term rate, for the days each shortfall remains unpaid. It is not a flat fine and it is not all-or-nothing.

That has two practical implications. A payment made a week late costs very little, so a missed date is worth correcting immediately rather than folding into the next installment. And a shortfall in the April period is the most expensive one, because it accrues for the longest.

If you have missed a date, the useful response is to pay as soon as you can and, if you draw a salary, consider increasing withholding for the rest of the year, since withholding is treated as paid evenly across the year regardless of when it occurred.

The bottom line

Put the four individual dates in a calendar as separate entries rather than a quarterly repeat, because the second period is two months long and June 15 is the one that gets missed. If you pay through a company, work from its fiscal year rather than the calendar, and note that a calendar-year corporation's final installment is due in December. Check whether the current year's dates have shifted for a weekend or holiday rather than reusing last year's calendar, and confirm your state's schedule separately, since it may have different dates, different proportions, or both.

Frequently asked questions

When are estimated tax payments due?

For individuals, April 15, June 15, September 15, and January 15 of the following year, moving to the next business day if a date falls on a weekend or legal holiday. Confirm the current year's dates rather than reusing an older calendar, since the shifts happen most years.

Can I skip the January payment?

Yes, if you file your return and pay the full balance due by January 31. This applies to individuals only. Corporations have no equivalent option, and their final installment is due in the twelfth month of the fiscal year.

When are corporate estimated tax payments due?

On the fifteenth day of the fourth, sixth, ninth, and twelfth months of the corporation's fiscal year. For a calendar-year corporation that means April, June, September, and December. Corporations do not follow the individual January date.

What if the due date falls on a weekend?

The payment is due on the next business day. Federal holidays have the same effect, and April 15 can also shift for a District of Columbia holiday in some years even when it falls on a weekday.

Do state estimated tax dates match the federal ones?

Often not. California uses three installments taking 30%, 40%, nothing, and 30%, so four equal payments on the federal schedule leave you underpaid. Other states differ in dates and thresholds, so each one needs checking separately.

What happens if I miss a payment date?

The charge accrues per period as interest on the amount underpaid, for the days it stays unpaid, rather than as a flat penalty. Paying as soon as you notice limits it. If you take a salary, increasing withholding also helps, because withholding is treated as paid evenly across the whole year.