Kentucky's K-4 is not a state version of the W-4 and it has no allowances to claim. It is an exemption certificate: four boxes, and most people should check none of them. Answer the questions below to find out which one applies to you, what it is worth in take-home pay, and whether you need to file the form at all.
None. Kentucky removed withholding allowances when it adopted its flat income tax, so the current Form K-4 has no allowance line at all — only four exemption checkboxes and a line for extra withholding you want taken out voluntarily. If you do not qualify for one of the four exemptions, you do not need to file a K-4, and your employer will withhold Kentucky tax at the flat rate after the standard deduction.
Four questions, drawn from the exemption instructions on form 42A804 (K-4)(12-2025). Nothing you enter leaves your browser.
A K-4 exemption stops Kentucky state withholding and nothing else. Federal tax, Social Security, Medicare and your city’s occupational tax all carry on. Here is the size of each.
| Annual | Normal withholding | With a K-4 exemption |
|---|---|---|
| Federal income tax | $4,420.00 | $4,420.00 |
| Kentucky state tax (3.5%) | $1,807.40 | $0.00 |
| Social Security | $3,410.00 | $3,410.00 |
| Medicare | $797.50 | $797.50 |
| Local occupational tax — Louisville 2.20% | $1,210.00 | $1,210.00 |
| Take-home pay | $43,355.10 | $45,162.50 |
The exemption is worth $1,807.40 a year. That is the entire effect of checking a box — the Kentucky state line, and nothing more.
$9,837.50 is still withheld. Federal tax, FICA and Louisville's occupational tax are untouched by the K-4. Local occupational tax follows where the work happens, not where you are domiciled, so even a reciprocal-state commuter or a Fort Campbell nonresident keeps paying it in full.
Put another way: the exemption removes about 16% of the tax withheld from your pay. “Exempt” on this form has never meant tax-free.
Estimates for the 2026 tax year, filing single with no pre-tax deductions. The current form, revision (12-2025), prints “a flat 3.5% rate with a standard deduction allowance of $3,360” — the same figures used above and by your employer’s payroll system. If the copy in front of you says 4% and $3,160, it is the superseded 2024 form; get the current one. Not tax advice.
The K-4 controls one line on your paycheck: Kentucky state income tax. Federal withholding is set by the federal W-4, and FICA and local occupational tax are not adjustable at all.
An exemption is not a deduction. Checking a box you do not qualify for does not lower your tax — it just moves the bill to April, with interest.
Local occupational tax survives every K-4 exemption, because Kentucky cities and counties levy it on wages earned inside their limits regardless of where you live or which state taxes your income.
Most people who search for “Kentucky K-4 allowances” are looking at a form revision from 2013. The allowance-based K-4 stopped existing when the flat tax came in.
1Work through the questions above to see whether any of the four exemptions applies to you.
2Download the current form from revenue.ky.gov — check the revision date, because older allowance-based copies are still circulating online.
3Fill in your name, address and Social Security number, then check only the box the helper identified. Leave all four blank if none applies.
4Complete the small worksheet that goes with your box: the reciprocal box needs you to name your state, the military-spouse box needs all six statements to be true, and the Fort Campbell box needs your state of residence.
5Add a dollar amount on the additional-withholding line if you want more Kentucky tax taken out — that is separate from the exemptions and does not require you to qualify for anything.
6Sign it and hand it to your employer's payroll contact, not to the Department of Revenue. Refile the no-liability exemption by February 15 next year if it still applies.
None — Kentucky's K-4 has no allowances. Kentucky eliminated withholding allowances when it moved to a flat income tax, and the current Form K-4 is purely an exemption certificate: four checkboxes plus a line for extra withholding you want taken out. If a page or a payroll form asks you for a number of Kentucky allowances, it is working from the 2013-era revision of the form.
Only if you are claiming one of the four exemptions or asking for additional withholding. The state's own employer instructions say an employer is required to keep a Form K-4 only to document an exemption request or an additional-withholding request. If neither applies to you, there is nothing to file and your employer withholds at the normal flat rate.
Your employer withholds Kentucky tax normally, using the flat rate and the standard deduction. You are not penalised and you are not switched to some maximum rate — that rule belonged to the old allowance-based form. The only thing you lose by not filing is an exemption you actually qualified for.
The reciprocal-state box. Kentucky has reciprocity with Illinois, Indiana, Michigan, West Virginia and Wisconsin outright, with Virginia if you commute daily, and with Ohio unless you are a 20%-or-greater shareholder-employee of an S corporation. You check that box, name your state on the form's worksheet, and Kentucky income tax stops being withheld — but local occupational tax does not, because that follows where the work happens.
No. It stops Kentucky state income tax only. Federal withholding, Social Security, Medicare and any city or county occupational tax keep coming out. On most Kentucky paychecks the state portion is the smallest of the four, which is why this page shows you the before-and-after in dollars rather than just telling you the box number.
The no-liability exemption expires on February 15 of the following year, so it has to be refiled annually. The Fort Campbell exemption has to be revoked within 10 days of becoming a Kentucky resident. The reciprocal-state and military-spouse exemptions last as long as the facts behind them stay true — tell your employer when they change.