How to pay Kentucky estimated taxes.

Kentucky collects its own estimated tax through the Kentucky Department of Revenue, separate from the IRS. Here’s who needs to pay, when, and how to pay online.

Do you need to pay?

You must generally make estimated payments if you expect to owe more than $500 in Kentucky tax for 2026 after withholding and refundable credits, and your withholding and credits will be less than the smaller of 90% of your 2026 tax or 100% of your 2025 tax. If you had no Kentucky tax liability for a full 12-month 2025, you don't have to pay estimates.

The required annual payment is the smaller of 90% of your 2026 tax (66 2/3% for farmers and fishermen) or 100% of your 2025 tax. If your 2025 Kentucky AGI was over $150,000 ($75,000 married filing separately), use 110% of the prior year tax.

If you underpay: Penalty equals the underpayment times the tax due interest rate, figured like the federal penalty. That rate is 9% for 2026.

For how to pick a safe amount, see how much to pay in estimated taxes.

Deadlines

Four installments due April 15, June 15, September 15, 2026, and January 15, 2027. This matches the federal schedule. If your obligation arises after September 1, you can skip the voucher by filing and paying in full by February 1, 2027.

Payment	Due
1st	April 15
2nd	June 15
3rd	September 15
4th	January 15 of the next year

A date on a weekend or holiday moves to the next business day. Pay at least two business days early.

Paying Kentucky, step by step

What you need

Nothing to set up. Kentucky Department of Revenue Electronic Payment (ePay) takes payments without an account.
Your Social Security number and a copy of last year's Kentucky return.
Your bank routing and account numbers.

Start at Kentucky Department of Revenue Electronic Payment (ePay), Kentucky's official payment site.

Go to the Department of Revenue's Electronic Payment site and click Get Started. No account is needed.
Fill in the Demographics section (name, address, phone, email).
Under Taxpayer Information, choose Tax Account Number as the account type and Individual Income Tax - Estimated Payment as the tax type; your account number is your SSN.
Enter your bank account (ACH) details and the amount. DOR says estimated payments can only be made by ACH.
Review, submit, and keep your confirmation.

Other ways to pay: Mail the 740-ES voucher with a check payable to Kentucky State Treasurer (write your SSN on the check). If you e-file, you can authorize DOR on Form 8879-K to debit all four installments on their due dates.

Kentucky will not fill these payments in for you. Your preparer has to enter each estimated payment on your Kentucky return. Keep your own record of the date, amount, and confirmation number.

Extension payments

Kentucky gives a six-month extension. If you have a federal extension, attach a copy to your Kentucky return; otherwise file Form 740EXT by the original due date. It does not extend the time to pay. Pay with the Kentucky Extension Payment Voucher (Section II of Form 740EXT); a late payment penalty may apply if less than 75% of the tax is paid by the original due date.

Make this year's first estimated payment as a separate transaction, marked as an estimate for the current year.

Good to know

Many Kentucky cities and counties charge their own occupational license taxes, which are separate from state estimates.
The 2026 flat rate on the 740-ES worksheet is 3.5%, and the standard deduction is $3,360.
The ePay page says it takes cards and eChecks, but DOR's estimated payments page says estimated payments are ACH only; a 1.5% fee applies to debit cards.
Moved this year? You may owe estimates to both Kentucky and your other state for the part of the year you lived or earned income in each.
Paying the IRS too? Follow the federal walkthrough. Other states each have a guide of their own.

Official sources

Checked October 2026 against the Kentucky Department of Revenue's own publications.

This guide is for general education and reflects rules as of October 2026. Tax law and agency websites change, and your situation may have details that change the answer. Please talk with your tax professional before acting on it.