Missed a quarterly estimated tax payment? How to catch up for 2026.

A question that comes up on tax forums every autumn, in one form or another: “I freelance as a side gig. I didn't pay taxes for Q2. Should I include those in Q3?” (r/tax, September 2026). The replies were helpful in pieces, but spread across several comments, and similar threads include confident advice that is simply wrong, such as “you cannot make an estimated tax payment beyond the due date”. This guide puts the official answer in one place, as a set of steps you can follow before the last 2026 deadline on January 15, 2027.

The short answer

• You can pay late, and you should pay soon. A late estimated payment is accepted and credited on the day you pay. It stops the penalty clock on the missed quarter, but it does not rewind it.
• The penalty works like interest. The IRS figures it separately for each installment, for the number of days it stayed unpaid, at the federal underpayment rate. That rate is 7% a year for October–December 2026.
• You may not owe a penalty at all. Check the $1,000 rule, the safe harbors, and the first-year exception before you panic.
• If you also have a W-2 job, extra withholding is the strongest fix. Withholding counts as paid evenly through the year for the penalty calculation.
• Uneven income? The annualized income installment method on Form 2210, Schedule AI, can reduce or remove the penalty for quarters when you earned little.

How the IRS treats a missed quarter

For 2026 there are four estimated tax payment due dates, listed in Form 1040-ES (2026): April 15, June 15 and September 15, 2026, and January 15, 2027. The IRS treats the year as four separate payment periods. Form 1040-ES says the penalty “is imposed on each underpayment for the number of days it remains unpaid”. So the year is not judged as one total. Each installment is tested on its own.

Two details from the current Instructions for Form 2210 matter for catching up:

• Payments are applied first to the earliest underpaid installment, even if you designate the payment for a later period. A payment you make in November for “Q3” pays off the April shortfall first.
• The penalty for an installment runs from its due date to the day it is paid, or to the return due date (April 15) if it is still unpaid.

The rate is the IRS underpayment rate, set every quarter. The IRS quarterly interest rates page lists these individual underpayment rates for 2026:

The rate for January–March 2027 had not been published when this page was written. At 7% a year, every $1,000 that stays unpaid costs about $5.75 per 30 days ($1,000 × 7% × 30 ÷ 365). That is not a disaster, but it adds up across three missed quarters and several months.

Step by step: catch up before January 15, 2027

1. Check whether you even owe a penaltyThe IRS (Topic no. 306) says most taxpayers avoid the penalty if they owe less than $1,000 after withholding and refundable credits, or if withholding and on-time estimated payments covered at least 90% of the 2026 tax or 100% of the tax on the 2025 return, whichever is smaller. If your 2025 AGI was over $150,000 ($75,000 married filing separately), the prior-year figure is 110%. And if you had no tax liability for all of 2025 as a U.S. citizen or resident alien, Form 1040-ES says you don't have to pay 2026 estimated tax at all. You still owe the tax when you file.
2. Work out your required annual paymentTake the smaller of (a) 90% of your expected 2026 total tax, or (b) 100% (or 110%) of your 2025 total tax. Publication 505 says the 2025 figure is Form 1040 line 24, minus a few specific items. Remember that “total tax” includes self-employment tax, which is line 9 of the 2026 Estimated Tax Worksheet in Form 1040-ES. For most people with a full 2025 return, option (b) is simply a number on last year's return, so it needs no forecasting.
3. Subtract what has already been paidAdd up your 2026 estimated payments, any 2025 overpayment you applied to 2026, and federal tax withheld from any W-2 job so far. Each installment is normally one-fourth of the required annual payment. The gap between what was due by September 15 and what you paid is your catch-up amount.
4. Pay the catch-up amount now, onlineUse IRS Direct Pay (free, from a bank account, no sign-in required), your IRS Online Account, EFTPS (you must enroll first), or a debit or credit card through one of the IRS card processors (the processor charges a fee). Choose estimated tax and the 2026 tax year, and keep the confirmation number. Online is safer than mailing a check: Form 1040-ES warns that the USPS postmark date may not be the day you drop the envelope off.
5. If you have a W-2 job, raise your withholding as wellThe Instructions for Form 2210 treat federal income tax withheld from wages as paid one-fourth on each due date, unless you choose to use actual dates. A larger withholding amount on your November and December paychecks therefore counts toward the April, June and September installments. A late estimated payment cannot do that. Give your employer a new Form W-4. The IRS Tax Withholding Estimator helps you pick the amount.
6. Handle the fourth installmentPay the January 15, 2027 installment on time. Alternatively, Form 1040-ES (2026) says you don't have to make that payment if you file your 2026 return by February 1, 2027 and pay the entire balance due with it. This option only covers the fourth installment. Penalties already built up on the first three still apply.
7. At filing time, choose how the penalty is figuredIf none of the special boxes on Form 2210 apply, you can let the IRS calculate the penalty and send you a bill (Form 2210 instructions). If most of your income came late in the year, the annualized income installment method (Form 2210, Schedule AI) recalculates each installment from the income you actually earned in that period. That often helps side-gig income that started mid-year. Form 1040-ES says that if you use it, you file Form 2210 with Schedule AI with your return even if no penalty is owed.
8. Check for a waiver only if one really fitsThe IRS says the penalty generally cannot be waived for reasonable cause. It may be removed or reduced after a casualty, disaster or other unusual circumstance, or if you retired after reaching age 62 or became disabled in the tax year or the year before and the underpayment was due to reasonable cause. Federally declared disaster areas may get postponed deadlines automatically.

Worked example

Jordan is a single freelance designer. All figures are illustrative.

• Jordan's 2025 Form 1040 shows total tax (line 24) of $8,000, and 2025 AGI was under $150,000.
• Jordan has no W-2 job, so nothing is withheld.
• Jordan expects about $11,000 of total 2026 tax, including self-employment tax. 90% of that is $9,900.
• The required annual payment is the smaller figure, $8,000, which means $2,000 per installment.
• Jordan paid nothing in April, June or September.

The table compares two choices. Both use the Form 2210 penalty worksheet method: underpayment × days unpaid ÷ 365 × the rate for each period.

Plan B's figures assume the January–March 2027 rate stays at 7%. That rate had not been published when this was written. Using only published rates, Plan B has already built up about $212 by December 31, 2026. In both plans Jordan still owes the remaining $3,000 of 2026 tax by April 15, 2027. That balance adds no estimated tax penalty, because the required installments are based on the smaller $8,000 prior-year figure.

If Jordan had a W-2 job instead and had an extra $8,000 withheld from the last paychecks of 2026, that withholding would count as $2,000 paid on each of the four due dates. The estimated tax penalty would be zero, even though the money left the paychecks in November and December.

Your real penalty comes from the 2026 Form 2210 or an IRS bill. This example only shows how timing changes the result.

Catch-up checklist

• ☐ Find your 2025 Form 1040 line 24 (total tax) and your 2025 AGI.
• ☐ Estimate your 2026 total tax, including self-employment tax, with the Form 1040-ES worksheet or your tax software.
• ☐ Pick the smaller safe-harbor target: 90% of 2026, or 100%/110% of 2025.
• ☐ Add up what you have paid: estimated payments, any applied 2025 overpayment, and W-2 withholding.
• ☐ Pay the shortfall for the first three installments now through Direct Pay, your Online Account or EFTPS. Choose the 2026 tax year and save the confirmation.
• ☐ If you have a W-2 job, file a new Form W-4 for extra withholding on your remaining 2026 paychecks.
• ☐ Calendar January 15, 2027, or plan to file and pay in full by February 1, 2027.
• ☐ If your income was uneven, ask your preparer about Form 2210, Schedule AI.
• ☐ Check your state's estimated tax rules separately.
• ☐ For 2027, put the IRS due dates in your calendar as soon as Form 1040-ES (2027) is out, and set money aside from every paid invoice.

Make next year boring

Most missed quarters come from cash that was never set aside, not from the rules themselves. Two habits help:

• Move a share of each paid invoice into a separate tax account the day it is paid. In Fjordbill, clients can pay an invoice online through your own Stripe account (Fjordbill does not process the card payment itself). The paid status and reports then show what actually came in each quarter.
• Track the estimate as you go. SovereignLedger, the companion app, maps receipts to Schedule C categories, keeps a mileage log, and estimates self-employment tax and quarterly payments, with the 1040-ES due dates in view. Paid Fjordbill invoices can be exported into it as income. See how the two apps work together.

Neither app files your return or sends money to the IRS. They are recordkeeping and estimating tools. For the paperwork side of 1099 income, see 1099 income and invoice records.

A related question from the same forum is whether a first-year freelancer can skip quarterly payments entirely (r/tax, September 2026). The first-year exception in step 1 answers it. Note that the exception depends on having no 2025 tax liability, not on whether you filed a 2025 return.

Frequently asked questions

Sources

• IRS, Form 1040-ES (2026), Estimated Tax for Individuals: due dates, February 1, 2027 rule, first-year exception, 110% rule, worksheet
• IRS, Instructions for Form 2210 (2025, the current edition): order payments are applied, withholding treated as paid one-fourth on each due date, Schedule AI, waivers, letting the IRS figure the penalty
• IRS, Form 2210, Underpayment of Estimated Tax by Individuals, Estates, and Trusts
• IRS Publication 505 (2026), Tax Withholding and Estimated Tax: required annual payment and 2025 total tax
• IRS Topic no. 306, Penalty for underpayment of estimated tax
• IRS, Underpayment of estimated tax by individuals penalty
• IRS, Quarterly interest rates (2026 underpayment rates)
• IRS, IR-2026-98: Interest rates remain the same for the fourth quarter of 2026
• IRS, Direct Pay with bank account
• IRS, Tax Withholding Estimator

Reviewed 13 November 2026. The worked example is illustrative and uses simple-interest arithmetic as in the Form 2210 penalty worksheet. Your result depends on your actual tax, payments and dates. Links go to the official source; check the live page in case a figure has changed.