How to Pay Quarterly Estimated Taxes

The IRS expects you to pay taxes four times a year — and penalizes you if you don't, even if you didn't know. I learned this the hard way. My first year of side hustling, I made $18K from DoorDash, didn't make a single quarterly payment, and got hit with an $1,800 underpayment penalty on top of a tax bill that was already $6K more than I expected. Nobody told me that when you're self-employed, you're also your own payroll department.

This guide covers who has to pay, when payments are due, three methods for calculating how much you owe, and the exact steps to submit your payment. I'll also cover a lesser-known W-4 strategy that can eliminate quarterly filing entirely if you have a day job.

What Are Quarterly Estimated Taxes?

The United States tax system operates on a pay-as-you-go basis. When you work a traditional W-2 job, your employer handles this for you by withholding income tax from every paycheck and sending it to the IRS on your behalf. You never think about it because it happens automatically.

When you earn self-employment income, there is no employer to withhold taxes for you. The responsibility falls on you to estimate what you owe and send payments to the IRS on a quarterly schedule. These payments cover two separate obligations:

• Federal income tax on your side hustle earnings, at your marginal tax rate
• Self-employment tax (Social Security and Medicare), which is 15.3% on net self-employment income up to the Social Security wage base, and 2.9% on income above that threshold

The quarterly estimated tax system applies to all types of income that are not subject to withholding. That includes freelance income, gig economy earnings, rental income, investment income, and any other money you receive without taxes taken out at the source.

Who Needs to Pay Quarterly Taxes?

There is a common misconception that quarterly estimated taxes are only for freelancers or business owners. In reality, the IRS requires quarterly payments from anyone who expects to owe $1,000 or more in tax when they file their annual return, after accounting for withholding and credits.

This applies to a wide range of people beyond just side hustlers:

• Freelancers and independent contractors receiving 1099-NEC income
• Gig workers driving for rideshare services, delivering food, or doing task-based work
• Sellers on platforms like Etsy, eBay, Amazon, or Poshmark
• Investors with significant capital gains or dividend income
• Landlords with rental income
• Retirees with pension or IRA distribution income that is not fully withheld

You do not need to make quarterly payments if you expect to owe less than $1,000 when you file, or if your withholding from a W-2 job covers at least 90% of your current year's tax liability (or 100% of last year's liability). This exception is what makes the safe harbor method so useful, which we will explain in the calculation section below.

2026 Quarterly Tax Due Dates

One of the most confusing aspects of quarterly estimated taxes is that the quarters are not evenly spaced. The IRS uses its own schedule, and the periods covered by each payment are not equal in length.

Payment	Period Covered	Due Date
Q1	January 1 - March 31	April 15, 2026
Q2	April 1 - May 31	June 15, 2026
Q3	June 1 - August 31	September 15, 2026
Q4	September 1 - December 31	January 15, 2027

Notice that Q2 only covers two months while Q3 covers three months and Q4 covers four months. Many side hustlers trip up by assuming each quarter is three months. Mark these dates in your calendar now, because missing them triggers penalties even if you eventually pay everything you owe.

If a due date falls on a weekend or federal holiday, the deadline moves to the next business day. There is also a special rule: if you file your annual return and pay all remaining tax by January 31, you can skip the Q4 payment due on January 15.

How to Calculate Your Quarterly Payment

There are three methods for calculating your quarterly payment. Each has tradeoffs in terms of simplicity, accuracy, and risk of underpayment penalties.

Method 1: Prior Year Safe Harbor

This is the simplest and most popular approach, especially for people whose income varies from year to year. The IRS provides a "safe harbor" rule: if you pay at least 100% of your prior year's total tax liability divided into four equal payments, you will not owe an underpayment penalty, regardless of how much you actually owe this year.

If your adjusted gross income (AGI) was above $150,000 last year ($75,000 if married filing separately), the safe harbor threshold increases to 110% of last year's tax.

Calculation: Take line 24 (total tax) from your most recent Form 1040. Divide by 4. That is your quarterly payment amount.

Method 2: Current Year Estimate

This method requires more work but can be more accurate if your income has changed significantly. You estimate your total income for the current year, calculate the tax you expect to owe, and divide by four. If you are not sure how to calculate your net self-employment income, our Schedule C explainer walks through the process line by line.

Steps:

1. Estimate your total annual income from all sources (W-2, side hustle, investments, etc.)
2. Subtract the standard deduction or estimated itemized deductions
3. Calculate income tax using the current year's tax brackets
4. Add self-employment tax (15.3% on 92.35% of net SE income)
5. Subtract your expected W-2 withholding and any credits
6. Divide the remaining amount by 4

The downside of this method is that if you underestimate your income and end up owing more than expected, you may face penalties.

Method 3: Annualized Income Method

If your income is highly uneven throughout the year, such as a seasonal business or a one-time large project, you can use the annualized income installment method. This lets you pay lower estimated taxes in quarters when you earn less and higher amounts in quarters when you earn more.

This method requires completing Form 2210 Schedule AI with your tax return. It is the most complex option and generally only worth the effort if your income is very lopsided across the year.

Worked Example

Let us walk through a realistic calculation for someone with both W-2 and side hustle income.

Situation: You earn $60,000 from a W-2 job and expect $25,000 in net side hustle income (after deducting business expenses). You are single and take the standard deduction.

Step 1: Calculate total income

• W-2 income: $60,000
• Net side hustle income: $25,000
• Deductible half of SE tax: $25,000 x 0.9235 x 0.0765 = $1,766
• Adjusted gross income: $60,000 + $25,000 - $1,766 = $83,234

Step 2: Calculate income tax

• Standard deduction (2026): $16,000
• Taxable income: $83,234 - $16,000 = $67,234
• Federal income tax (approximate): $10,600

Step 3: Calculate self-employment tax

• Net SE income x 0.9235 = $25,000 x 0.9235 = $23,088
• SE tax: $23,088 x 15.3% = $3,532

Step 4: Determine quarterly payment

• Total tax: $10,600 + $3,532 = $14,132
• W-2 withholding (estimated from $60K salary): approximately $7,500
• Remaining tax to cover through estimated payments: $14,132 - $7,500 = $6,632
• Quarterly payment: $6,632 / 4 = $1,658 per quarter

In this scenario, you would need to send approximately $1,658 to the IRS four times per year to stay current on your tax obligations.

How to Actually Pay

Once you know how much to pay, you need to actually send the money to the IRS. There are several payment methods, each with different advantages.

IRS Direct Pay

The simplest method for most people. Go to irs.gov/directpay, select "Estimated Tax" as the payment type, enter your bank information, and submit. The payment is free, processes in one business day, and you get immediate confirmation. No account registration is required.

EFTPS (Electronic Federal Tax Payment System)

EFTPS requires a one-time enrollment that takes about a week (they mail you a PIN). Once enrolled, you can schedule payments in advance, set up recurring payments, and view your complete payment history. This is the best option if you want to automate your quarterly payments so you never forget a deadline.

Form 1040-ES Payment Vouchers

If you prefer to pay by mail, you can print estimated tax vouchers from Form 1040-ES and mail them with a check to the IRS. This is the slowest method and offers no immediate confirmation, but some people prefer the tangibility of writing a check. Mail payments to the address listed on the voucher for your state.

Credit or Debit Card

You can pay through IRS-approved payment processors. Debit card payments carry a flat fee of about $2.50. Credit card payments are charged a processing fee of roughly 1.85% to 2%. Unless you are earning significant credit card rewards that outweigh the fee, paying by card is generally not cost-effective. However, it can be useful if you need a few extra weeks before the money leaves your bank account due to the credit card billing cycle.

What Happens If You Don't Pay

If you do not make quarterly estimated tax payments and owe more than $1,000 when you file your annual return, the IRS will assess an underpayment penalty. This penalty is essentially interest on the amount you should have paid, calculated from each quarterly due date until you actually pay.

The underpayment penalty rate is set quarterly by the IRS and is tied to the federal short-term rate plus 3 percentage points. As of early 2026, this rate is approximately 8% per year. The penalty is calculated separately for each quarter, so being late on Q1 does not affect your Q3 calculation.

Here is roughly what the penalty looks like in practice: if you should have paid $2,000 in Q1 but paid nothing, and you eventually pay that amount when you file in April of the following year, the penalty on that one quarter would be approximately $160 (8% of $2,000 for one year). Across all four quarters, the cumulative penalty can add up quickly.

The penalty is reported on Form 2210. Tax software will calculate this for you automatically when you file your return.

Adjusting W-2 Withholding Instead

Here is a strategy that many side hustlers overlook: if you also have a W-2 job, you can increase the federal tax withholding from your paycheck to cover your side hustle tax liability. This completely eliminates the need to make separate quarterly payments.

To do this, submit a new Form W-4 to your employer. In Step 4(c), enter an additional dollar amount you want withheld from each paycheck. If you need to cover an extra $6,632 per year in taxes (from our example above), and you are paid biweekly (26 paychecks), you would enter $255 as the additional withholding amount.

The advantage of this approach is significant: W-2 withholding is treated by the IRS as if it were paid evenly throughout the year, even if the additional withholding only starts mid-year. This means you will not face underpayment penalties for earlier quarters, even if you just increased your withholding in September.

This is one of the most under-discussed benefits available to side hustlers who also hold W-2 employment. It simplifies your tax life considerably, since you only need to adjust your W-4 once per year and then let your employer handle the rest.

The drawback is smaller paychecks. You are effectively choosing to receive less take-home pay in exchange for not having to manage quarterly payments. For many people, that trade-off is worth it.

Tracking and Planning Tips

Staying on top of quarterly taxes requires a bit of ongoing discipline. Here are practical strategies that work well for side hustlers.

Set Aside 25-30% of Every Payment

Whenever you receive side hustle income, immediately transfer 25-30% to a separate savings account. This covers both income tax and self-employment tax for most people in the 22-24% tax bracket. If you are in a higher bracket, set aside more. The point is to never spend money that belongs to the IRS.

Better yet, automate the whole thing. I use Relay's sub-accounts — one for tax savings, one for operating expenses, one for owner's pay — and set up automatic allocation rules so every deposit gets split the moment it hits. The money earmarked for taxes is physically separated from my spending money before I even see it. When the quarterly deadline arrives, the payment is already sitting there. As a bonus, if you park your tax savings in a high-yield savings account, you earn interest while you wait.

Use Accounting Software Estimates

If you use accounting software like TurboTax Self-Employed or QuickBooks Self-Employed, these tools can estimate your quarterly tax obligation based on your actual income and expenses throughout the year. This takes the guesswork out of calculations and adjusts as your income changes.

Review and Adjust Quarterly

Before each quarterly payment, take 15 minutes to review your actual income for the period and compare it to your estimates. If your side hustle income is significantly higher or lower than expected, adjust your payment. It is better to slightly overpay (you will get a refund) than to underpay and face penalties.

For more detailed guidance on organizing your side hustle finances, see our guide on how to track side hustle income and expenses. If you are looking for deductions to lower your tax bill, our side hustle tax deductions guide covers everything you can legitimately write off.

Related reading: The Complete Side Hustle Tax Guide | Side Hustle Tax Deductions | How to Track Income & Expenses | TurboTax Self-Employed Review