What are estimated taxes? Explained like four rent days a year

No. 01The rent day you already understand

In shortSame rent either way. The only difference is whether someone takes it out for you or you have to remember.

Picture two tenants in the same building paying the same rent.

The first has an arrangement with the landlord: rent comes out of each paycheck before it is deposited. The tenant never sees the money, never has to remember a date, and never feels rich on payday, because the number in the account is already the number that is theirs. That is every W-2 employee you have ever met.

The second tenant gets the whole paycheck. The full amount lands, nothing taken out, and it looks wonderful. But the landlord still wants the rent, and this landlord collects only four times a year. If the tenant spent the rent on the way to the fourth collection, the landlord does not care how good the quarter looked in the middle. The tenant owes it, plus a late fee.

The second tenant has exactly one trick: move the rent money to a separate jar the day the paycheck lands, before it starts feeling like spending money.

01

The gross number feels like yours for about ninety days. Then rent day.

No. 02Now the contractor version

In shortExpect to owe $1,000 or more and the IRS wants it in four payments on Form 1040-ES, due April 15, June 15, September 15, and January 15.

Swap the landlord for the IRS and the rent for income tax plus self-employment tax, and that is estimated tax. A commission check to an independent contractor arrives with nothing withheld. The tax is still owed; it is just owed by you, during the year, in four pieces.

Who has to do this: anyone who expects to owe $1,000 or more in federal tax for the year after subtracting any withholding and credits.¹ For a full-time contractor paid by commission, that is nearly everyone.

The form is Form 1040-ES, Estimated Tax for Individuals: a worksheet to figure the amount, and four payment vouchers. Most people now pay online and never print the vouchers.

The four rent days for 2026 income: April 15, 2026; June 15, 2026; September 15, 2026; and January 15, 2027.² Notice the spacing. The gap between the first and second is two months; the gap between the third and fourth is four. They are called quarterly payments, and they are not quarterly.

The long version, with the self-employment tax arithmetic on $80,000 of commission, is here.

No. 03The safe harbor, in plain words

In shortPay in at least 90 percent of this year’s tax, or 100 percent of last year’s, across the four dates, and there is no penalty even if you still owe in April.

Here is the part that calms most first-year contractors down. The IRS does not expect you to guess your commission year perfectly. It sets a floor. If your four payments add up to at least the smaller of two numbers, 90 percent of what you end up owing for 2026 or 100 percent of what you owed for 2025, there is no underpayment penalty.³ You still pay whatever is left in April, but there is no late fee on it.

For someone leaving W-2 work this year, that second number is a gift. You know exactly what your 2025 tax was; it is on last year’s return. Pay that amount across the four dates and the penalty question is settled, however the commission year turns out.

No. 04Where people get burned

In shortSpending the gross, then discovering on rent day that a share of it was never yours.

The burn is always the same one: treating the gross as take-home. A commission check with nothing withheld is bigger than any paycheck you have seen, and for about ninety days it behaves like income. Then the rent day comes and the money has become a car payment.

The second burn is milder but real: missing a date because nobody sent a reminder. There is no landlord knocking. The IRS says you may pay weekly, every other week, or monthly if that is easier, as long as enough has arrived by each due date. For a contractor whose checks come at odd intervals, paying something every time a check lands is simpler than remembering four dates.

The one place the story breaks is that rent is a fixed number the landlord tells you. Tax is a share of what you earned, and nobody tells you; you estimate it, hence the name. That is why the separate account matters more than the calendar. Our rule of thumb, from the long read this piece belongs to, is a quarter of every commission check into a separate account the day it arrives, with a tax preparer adjusting the share once they have seen your first real quarter. This is an explanation, not tax advice; the preparer gets the last word.

No. 05The one question to ask

In short“What share of each check should I set aside, and which of the four dates is my first one?”

Ask a tax preparer in your first month as a contractor, not in April: “What share of each check should I move to the tax account, and which payment date is my first?” A straight answer is a percentage and a date. If the preparer asks what you paid in tax last year before answering, they are doing it right; that number is the safe harbor.

The Kenswick Partners is a journal, and partner agencies may compensate us when a reader asks to be introduced to them; at most of them, agents are independent contractors paid by commission, which is why we wrote this one down.