When you have a regular W-2 job, taxes happen in the background. Your employer withholds money from every paycheck, sends it to the IRS, and by the time April rolls around, you either owe a little or get a refund. Simple enough.
But when you are a freelancer, contractor, or any kind of self-employed person, nobody withholds anything. The money hits your account in full, and it is on you to set aside what you owe and send it to the IRS yourself. And here is the kicker — the IRS does not want to wait until April to get paid. They expect you to pay as you earn, four times a year.
These are called quarterly estimated tax payments, and if you skip them (or underpay them), you will face penalties. Let us walk through how they work, when they are due, and how to calculate what you owe — without losing your mind.
Why Do Quarterly Taxes Exist?
The US tax system is a "pay-as-you-go" system. That means taxes are supposed to be paid throughout the year as you earn income, not in one lump sum at the end. For employees, this happens through payroll withholding. For self-employed people, it happens through quarterly estimated payments.
The general rule is: if you expect to owe $1,000 or more in federal taxes for the year (after subtracting withholding and credits), you are required to make quarterly payments. Ignore this, and the IRS charges an underpayment penalty — essentially interest on the taxes you should have paid throughout the year.
When Are Quarterly Payments Due?
Despite the name "quarterly," the payment periods are not evenly spaced. Here are the due dates for the 2025 tax year:
- Q1 (January 1 – March 31): Due April 15, 2025
- Q2 (April 1 – May 31): Due June 16, 2025
- Q3 (June 1 – August 31): Due September 15, 2025
- Q4 (September 1 – December 31): Due January 15, 2026
Notice that Q2 only covers two months (April and May), while Q3 covers three months (June, July, August), and Q4 covers four months (September through December). The IRS is not great at naming things — just mark these dates on your calendar and do not miss them.
If a due date falls on a weekend or holiday, the deadline moves to the next business day.
How to Calculate Your Quarterly Payments
There are two main approaches, and you should use whichever results in the lower payment to avoid penalties:
Method 1: Based on last year's tax (the "safe harbor"). Pay 100% of last year's total tax liability, divided into four equal payments. If your AGI last year was over $150,000 ($75,000 if married filing separately), you need to pay 110% of last year's tax instead. This is the easiest method because you already know the number — just look at your prior year tax return, line 24 (total tax).
Method 2: Based on this year's estimated tax. Estimate your income, deductions, and credits for the current year, calculate 90% of what you expect to owe, and divide by four. This method can result in lower payments if you expect to earn less this year than last year, but it requires more guesswork.
As long as you pay at least the lesser of these two amounts, you will not face an underpayment penalty — even if you end up owing more when you file your return.
Our quarterly tax calculator does all of this math for you. Just enter your expected income and expenses, and it tells you exactly how much to pay each quarter.
What Taxes Are Included in Quarterly Payments?
Your quarterly estimated payment covers multiple types of tax:
- Federal income tax — based on your tax bracket
- Self-employment tax — the 15.3% Social Security and Medicare tax that self-employed people pay
Do not forget about state taxes either. Many states also require quarterly estimated payments if you are self-employed. The amounts and due dates vary by state, so check your state's tax authority website.
To get a full picture of your self-employment tax burden, use our self-employment tax calculator.
How to Actually Make the Payments
The IRS gives you several ways to pay:
- IRS Direct Pay (irs.gov/payments): Free electronic payment directly from your bank account. This is the easiest option for most people.
- EFTPS (Electronic Federal Tax Payment System): A free system for making federal tax payments. You need to enroll in advance at eftps.gov.
- Credit or debit card: You can pay through approved payment processors, but they charge a convenience fee (about 1.85–1.98% for credit cards).
- Check or money order: Mail it with a payment voucher (Form 1040-ES) to the address listed in the instructions. This is the slowest method and gives you no instant confirmation.
When you make a payment, make sure you select "Estimated Tax" as the payment type and choose the correct tax year and quarter. Keep confirmation numbers and receipts for your records.
What Happens If You Do Not Pay?
If you do not make quarterly payments (or you underpay), the IRS charges an underpayment penalty. This penalty is essentially interest on the amount you should have paid, charged from the due date of the missed payment until you actually pay it.
The penalty rate changes quarterly and is based on the federal short-term interest rate plus 3 percentage points. As of early 2025, it is around 7–8%. That is not a catastrophic amount, but it is money you are throwing away for no reason.
The IRS calculates the penalty on Form 2210 when you file your return. In some cases — if your income was uneven throughout the year — you might be able to reduce the penalty by using the "annualized income installment method" to show that you paid the right amount at the right time based on when you actually earned the income.
Tips for Making Quarterly Taxes Less Painful
Set aside money with every payment you receive. This is the single best habit you can build. Every time a client pays you, immediately transfer 25–30% into a separate savings account earmarked for taxes. When quarterly payments come due, the money is already there. No scrambling, no stress.
Open a separate bank account for taxes. Having a dedicated tax savings account makes it much easier to track how much you have set aside. It also prevents you from accidentally spending your tax money on other things. Our freelancer rate calculator can help you figure out the right rate to charge so your take-home pay covers your expenses after taxes.
Track your income and expenses throughout the year. Do not wait until tax time to add everything up. Use a simple spreadsheet, an app like QuickBooks Self-Employed, or even a notebook. The more accurately you track your income and expenses, the more accurately you can estimate your quarterly payments.
Adjust your payments mid-year if needed. If your income is significantly higher or lower than expected, you can adjust your quarterly payments. There is no penalty for overpaying — if you send too much, it just gets applied as a credit when you file your return.
Consider increasing your W-2 withholding. If you have a day job in addition to your freelance work, you can ask your employer to withhold extra federal tax from your paycheck. This can reduce or eliminate the need for separate quarterly payments. Just update your W-4 and specify an additional amount to withhold each pay period. Our payroll calculator shows how changes to your withholding affect your paycheck.
What If Your Income Is Uneven?
A lot of freelancers earn wildly different amounts from quarter to quarter. Maybe you had a great Q1 but a slow Q3. Or maybe you landed a big project in Q4 that doubled your usual income. The standard method of paying four equal installments does not always make sense.
In that case, you can use the annualized income installment method (Form 2210, Schedule AI). This lets you calculate each quarterly payment based on the income you actually earned during that specific period, rather than assuming your income is spread evenly throughout the year. It is a bit more work, but it can save you from making unnecessarily large payments in slow quarters.
The Bottom Line
Quarterly estimated taxes are one of those things that seems intimidating at first but becomes routine once you set up a system. The key steps are simple: set aside money consistently, track your income and expenses, and make your payments on time.
The worst thing you can do is ignore it. A little planning now saves you from a big, stressful tax bill — plus penalties — later.
Start by running your numbers through our quarterly tax calculator. It will tell you exactly how much to pay and when. And if you are still sorting out your overall tax picture, our 1099 tax calculator gives you a comprehensive estimate of everything you owe.