General information, not tax advice. Rules change and individual circumstances differ. Confirm anything here with a qualified accountant or your own tax authority before relying on it.
Why freelancers pay four times a year
When you are employed, your employer withholds tax from every payslip and sends it on. Nobody withholds anything from a freelance invoice. The United States tax system, like many others, works on a pay-as-you-earn basis, so it expects self-employed people to estimate and pay tax on income during the year it is earned rather than in one lump the following spring.
That is what estimated quarterly taxes are. They are not an extra tax, and they are not optional above a low threshold. They are the same tax an employee pays, arriving in four instalments you send yourself.
The part that catches people out: self-employment tax
Income tax is the familiar half. Self-employment tax is the half that surprises people in their first year.
Employees pay 7.65 percent of their wages towards Social Security and Medicare, and their employer pays a matching 7.65 percent. When you work for yourself you are both parties, so you pay the whole 15.3 percent. It is charged on 92.35 percent of your net profit, and it applies before any income tax is calculated.
On $80,000 of net profit, that is roughly $11,300 in self-employment tax alone, before a single dollar of income tax. Half of it is deductible against your income tax, which softens the blow slightly, but the cash still has to leave your account.
This is the single biggest reason a rate that looked comparable to a salary turns out not to be. The freelance versus full-time calculator shows the difference explicitly.
How much to set aside
The common rule of thumb is 25 to 30 percent of net profit, meaning income after business expenses rather than total invoiced revenue. It is a reasonable starting point and a poor finishing point, because the right figure depends on your total income, your filing status, your deductions and where you live.
- Lower end, around 25 percent. Modest profit, a state with no income tax, meaningful deductions.
- Middle, 30 percent. A typical full-time freelance income in a state with moderate tax.
- Higher, 35 to 40 percent. Higher earnings pushing into upper brackets, or a high-tax state such as California or New York.
The quarterly tax calculator works this out from real 2026 federal brackets and your state rather than from a rule of thumb, which matters more the further you are from the middle of the range.
The actual due dates
US estimated payments are generally due on the 15th of April, June, September and January, with the January payment covering the final quarter of the previous year. Dates shift by a day or two when the 15th falls on a weekend or a public holiday, so check the current year rather than assuming.
Two things about this schedule surprise people. The quarters are not equal: the second covers two months, not three. And the year does not end in December for this purpose, because the final payment lands in the following January.
Outside the United States, the concept of paying through the year is common but the schedule is not. The UK uses two payments on account in January and July, Canada uses quarterly instalments in March, June, September and December, and Australia uses quarterly BAS statements. Check your own tax authority rather than assuming the US pattern applies.
The safe harbour rule, which solves most of the anxiety
The hardest part of estimating tax is that freelance income is unpredictable. You are being asked in April to estimate what you will earn by December.
The safe harbour rule removes most of that problem. If you pay at least 100 percent of the total tax shown on last year's return, spread across the four instalments, you generally will not face an underpayment penalty no matter how much more you earn this year. If your adjusted gross income last year was above $150,000, the threshold is 110 percent instead.
This is the practical approach for anyone with a volatile income. Take last year's total tax, divide by four, pay that each quarter, and settle any difference when you file. You may owe more in April, but you will not be penalised for it.
There is a second safe harbour based on paying 90 percent of the current year's tax, which suits people whose income has fallen sharply and who do not want to overpay against a bigger previous year.
What actually happens if you miss a payment
Less than most people fear. Missing or underpaying an instalment produces a penalty calculated much like interest on the amount underpaid, for the period it was late. It is not the same as failing to file, and it does not trigger anything dramatic.
That said, it accrues, it is entirely avoidable, and it is charged per quarter, so a missed April payment accumulates for longer than a missed January one. If you have missed one, paying as soon as you can reduces the amount rather than waiting for the next scheduled date.
A system that survives a busy month
The mechanism matters more than the intention. A system that depends on remembering will fail in a month when you are busy, which is exactly the month with the most income to set aside.
- Open a separate savings account used only for tax. Not a sub-label on your current account. A separate account you do not have a card for.
- Transfer the percentage the day an invoice clears. Not weekly, not monthly. The same day, while the money is still psychologically the client's rather than yours.
- Put the four dates in a calendar with a reminder two weeks ahead. The reminder needs to arrive while you can still act on it.
- Keep expenses recorded as you go. Tax is charged on profit, so unrecorded expenses mean overpaying. The expense guide covers a five-minute weekly habit.
- Talk to an accountant once a year. Even when your situation feels simple, one conversation usually pays for itself in missed deductions alone.
The goal is for the tax money to disappear from your daily spending decisions as early as possible, so no due date ever arrives as a surprise.
A note on your first year
In your first year of freelancing there is no previous return to base a safe harbour on, which is the one situation where estimating properly is unavoidable. Estimate conservatively, set aside on the high side, and recalculate each quarter as the picture clarifies. Overpaying is annoying; underpaying with no safe harbour behind you is expensive.