How to fill out Form W-4 (2026): step by step, for employers

Tax forms › Form W-4 · Last reviewed October 25, 2026 · General information, not tax advice

Form W-4 at a glance

What it does	Tells you how much federal income tax to withhold from an employee's pay
Who completes it	The employee; you keep it
When	Before the first paycheck, and whenever the employee wants to change withholding
Filed with the IRS?	No, unless the IRS asks for it
Exempt employees	A new form for 2027 by Tue, Feb 16, 2027 (Feb 15 is Presidents' Day)

What Form W-4 is

Form W-4 is the employee's instructions for federal income tax withholding. You apply it with the tables in IRS Publication 15-T. It has no allowances since 2020: instead it asks for filing status, multiple jobs, credits and other adjustments in dollars.

For 2026, Step 3 uses $2,200 for each qualifying child under 17 (up from $2,000) and $500 for other dependents, the Deductions Worksheet covers the new deductions for tips, overtime, car loan interest and seniors, and exemption from withholding is claimed with a checkbox below Step 4(c).

Who has to file

Every new employee completes a W-4 before you pay them. If they do not, withhold as if they were single or married filing separately with no other entries.
Existing employees do not need a new W-4 each year unless they claimed exemption, which lasts only for the calendar year.
Contractors do not complete a W-4; they give you a W-9.

Due dates

What	Due
New employee	On or before the first day of work, and in any case before the first payroll
Change of withholding	Put it into effect no later than the start of the first payroll period ending 30 or more days after you receive it
Employee claiming exemption for 2027	A new W-4 by Tue, Feb 16, 2027; otherwise withhold as single with no adjustments

Penalties for filing late or wrong

An employee who makes a statement on Form W-4 with no reasonable basis that reduces withholding can be charged a $500 civil penalty.
Employers who do not withhold correctly from a valid W-4 can be liable for the tax they should have withheld.
The IRS can send a lock-in letter setting the maximum withholding for an employee; you must follow it.

Form W-4 step by step

Step	What the employee enters	What you do with it
1(a), (b)	Name, address and Social Security number	Set up the employee record; the name should match their Social Security card
1(c)	Filing status: single or married filing separately, married filing jointly or qualifying surviving spouse, or head of household	Choose the matching withholding table in Publication 15-T
2	Multiple jobs or a working spouse: use the IRS estimator, the Multiple Jobs Worksheet (result goes in 4(c)), or tick the box for two jobs	If the box is ticked, use the higher-rate checkbox tables in Publication 15-T
3	Credits: $2,200 per qualifying child under 17 and $500 per other dependent, if total income is $200,000 or less ($400,000 married filing jointly)	Subtract the annual amount from the tentative annual withholding
4(a)	Other income without withholding, such as interest or dividends	Add it to annualized wages
4(b)	Deductions above the standard deduction, from the Deductions Worksheet	Subtract it from annualized wages
4(c)	Extra withholding per pay period	Add it to each paycheck's withholding
Exempt	Checkbox: no tax liability last year and none expected this year	Withhold no federal income tax for 2026; Social Security and Medicare still apply
5	Signature and date	An unsigned W-4 is not valid
Employers only	Your name, address, EIN and the first date of employment	Fill in for new hires; also used for new-hire reporting to your state

Common mistakes

Using an old W-4 table or an allowance-based method for a 2020-or-later form.
Ignoring the Step 2 checkbox, which needs the checkbox withholding tables.
Keeping an exempt employee exempt into the new year without a new form.
Accepting an unsigned form or one with Step 3 filled in by an employee above the income limit.
Treating the W-4 as a reason to skip new-hire reporting to the state; that is a separate requirement.

How to file Form W-4

Give the employee the current form. Hand out the 2026 Form W-4 at hire, with the instructions, or provide it electronically if you have an approved system.
Check it is complete and signed. Look at Step 1, any Steps 2 to 4 that apply, and the signature. Do not advise the employee what to enter.
Enter it in payroll. Set the filing status, Step 2 choice, Step 3 credits and Step 4 amounts in your payroll system.
Withhold using Publication 15-T. Calculate federal income tax with the percentage method or wage bracket tables for the employee's entries.
Keep it on file. Keep the W-4 for at least four years after the last tax it relates to. Send it to the IRS only if asked.

How AcboBooks fills it in

AcboBooks 0.2.1 does not produce or store the W-4 form itself. The employee record has a "W-4 on file" checkbox in its HR documents list.

On Run Payroll, the US edition has a W-4 filing status choice (single or married filing separately, married filing jointly, head of household), a dependents field, and an Estimate Federal WH button that works out withholding with the 2026 Publication 15-T percentage-method tables. You can always type over the result.

What it leaves to you

The Step 2 checkbox and Step 4(a), 4(b) and 4(c) entries are not on that screen in 0.2.1. For employees who use them, work out the withholding with Publication 15-T and enter it on the paycheck.
Check the first paycheck of the year, and any paycheck after a new W-4, against Publication 15-T.

The Run Payroll screen in AcboBooks, US edition — Run Payroll in AcboBooks (US edition), with the W-4 filing status and the Pub 15-T estimate. The form worksheets are built from these paychecks.

Described as of AcboBooks 0.2.1. See US payroll in AcboBooks

Questions

Do employees need to fill out a new W-4 for 2026?

No. A W-4 stays in effect until the employee gives you a new one. The exception is an employee who claimed exemption: that lasts only for the year, so they need a new form by February 16, 2027 to stay exempt in 2027.

What if a new employee does not give me a W-4?

Withhold as if they checked single or married filing separately and made no entries in Steps 2 to 4.

What changed on the 2026 Form W-4?

Step 3 now uses $2,200 for each qualifying child under 17, the Deductions Worksheet includes the new deductions for qualified tips, overtime, car loan interest and seniors, and exemption is claimed with a checkbox instead of writing "Exempt".

Can I help an employee fill out their W-4?

You can explain what the form asks and point them to the IRS Tax Withholding Estimator, but you should not tell them what to enter; the choices depend on their own tax situation.

Do I send W-4s to the IRS?

No. Keep them in your records. The IRS may ask for a specific employee's W-4 and can send a lock-in letter that you must follow.

Sources

Checked against these sources on October 25, 2026. Dates assume a calendar year and apply the next-business-day rule for weekends and holidays.

General information, not tax or legal advice. Forms, thresholds and dates change; confirm with the IRS and SSA or a tax professional before you file.

How to fill out Form W-4