W-2 vs. W-4: The Two IRS Forms Payroll Runs On

A restaurant owner in Spring called me the week she hired her first two employees. She had them both fill out a “tax form,” gave them a copy of the same PDF, and told them to sign it. One employee needed a W-4. The other, six months later at tax time, needed a W-2. She’d handed them the wrong form and didn’t know it until her payroll provider flagged it.

This mix-up is common, and it happens because W-2 and W-4 sound almost identical and get used at opposite ends of the payroll process. Here’s what each one actually does, who fills it out, and how they connect.

The One-Sentence Version

W-4 is what an employee fills out before getting paid. It tells the employer how much tax to withhold.

W-2 is what the employer fills out after the year ends. It reports what the employee actually earned and what actually got withheld.

One is a forecast. The other is a record.

What a W-4 Actually Is

Form W-4, officially the “Employee’s Withholding Certificate,” is completed by the employee, not the employer. A new hire fills one out before their first paycheck. It answers one question for the employer’s payroll system: how much federal income tax should come out of each check?

What Goes On It

The current W-4 (redesigned in 2020, no longer using “allowances”) asks for:

• Filing status (single, married filing jointly, head of household)
• Whether the employee holds a second job or their spouse also works
• Number of qualifying dependents, converted into a dollar credit amount
• Any other income not from a job (interest, dividends, retirement)
• Additional amount the employee wants withheld each pay period

The employer plugs these answers into IRS withholding tables (or payroll software does it automatically) to calculate the tax taken from every paycheck.

When It Gets Filled Out

• Before the first paycheck at a new job
• Any time an employee’s situation changes: marriage, divorce, a new child, a second job, a spouse starting work
• Whenever an employee wants to adjust how much comes out, whether that’s withholding more to avoid an April tax bill or less to keep more in each check

There’s no limit on how often someone can submit a new W-4. If no W-4 is on file, the IRS requires the employer to withhold at the highest default rate, single with no adjustments, until one shows up.

What a W-2 Actually Is

Form W-2, the “Wage and Tax Statement,” moves in the opposite direction. The employer fills this one out, not the employee, and it happens after the fact.

At year-end, the employer pulls everything paid to that employee all year (wages, tips, bonuses) and everything withheld (federal income tax, Social Security, Medicare, state amounts if applicable) and reports it on a W-2.

What Goes On It

• Total wages, tips, and other compensation for the year
• Federal income tax withheld
• Social Security and Medicare wages and tax withheld
• State and local wages and withholding, if applicable
• Retirement plan contributions, HSA contributions, and a handful of other coded boxes

The Deadline That Trips People Up

Employers must send W-2s to employees and file them with the Social Security Administration by January 31 of the following year. Miss it, and penalties start accruing per form, increasing the longer the form is late. Unlike a lot of IRS deadlines, there’s very little wiggle room on this one.

W-2 vs. W-4, Side by Side

	W-4	W-2
Who fills it out	Employee	Employer
When	Before the first paycheck, or any time a situation changes	After the calendar year ends
Purpose	Sets withholding going forward	Reports what actually happened
Filed with the IRS?	No, kept in employer’s records	Yes, filed with the SSA and IRS
Deadline	Before hire; anytime after	January 31
What it changes	Future paychecks	Nothing. It’s a record, not an instruction

How the Two Forms Work Together

Picture the whole year as one loop.

A new employee starts. She fills out a W-4. Her employer uses that information to calculate withholding on every paycheck for the rest of the year, or until she submits a new one. Twelve months of paychecks go by, each one shaped by what she put on that form.

Then January arrives. The employer looks back at everything actually paid and actually withheld across those paychecks and reports the total on a W-2. That W-2 is what she uses to file her personal tax return, comparing what was withheld against what she actually owes.

If the W-4 was filled out accurately, the W-2 numbers line up close to her real tax liability, and she owes little or gets a small refund. If the W-4 was wrong, whether too few allowances withheld too much or a life change was never updated, the W-2 reflects that mismatch, and she finds out at filing time.

Where Houston Businesses Get This Wrong

Treating them as interchangeable. They’re not the same form at different points in time. A W-4 is an instruction. A W-2 is a report. Handing an employee a W-2 template to fill out at hiring, like the restaurant owner did, produces a document with none of the information payroll actually needs.

Never updating W-4 defaults. An employee gets married, has a kid, or picks up a second household income, but never files a new W-4. Their withholding stays set for a situation that no longer exists. This isn’t the employer’s job to catch, but it’s worth reminding staff once a year that they can update it.

Confusing W-2 workers with 1099 contractors. Not everyone who does work for a business gets a W-2. Independent contractors get a 1099-NEC instead, and misclassifying the two carries real IRS penalties. See our guide to employee vs. independent contractor classification if that line isn’t clear for your team.

Missing the January 31 W-2 deadline. This one is purely a calendar problem. Payroll needs to be reconciled well before year-end so W-2s can go out on time, not scrambled together in the last week of January.

Guessing at withholding instead of using the tables. Manually estimating withholding instead of running it through current IRS tables or payroll software produces W-2s that don’t match what employees actually owed, generating complaints and, occasionally, corrected W-2s.

If a W-2 Is Wrong

Mistakes happen. Wrong Social Security number, wrong wage amount, wrong box checked. The fix is a Form W-2c, a corrected wage statement, filed with the SSA and reissued to the employee. There’s no equivalent “correction” for a W-4, since it’s not filed with the IRS in the first place. If a W-4 was wrong, the employee simply submits a new one, and the change applies going forward.

Getting Payroll Right From the Start

Both forms are simple on paper. What trips up Houston small businesses is the process around them: making sure every new hire has a W-4 on file before the first check runs, keeping withholding current as employees’ lives change, and getting accurate W-2s out the door by January 31 every year without a scramble.

If you’re also deciding whether your LLC should elect S-corp tax treatment, that decision changes how you get paid from your own business and brings its own W-2 requirements. Our guide to Form 2553 walks through that election, the deadlines, and what changes once it’s in place.

We run payroll for small businesses across Houston, from onboarding paperwork through year-end W-2s. If you’d rather hand this off than manage W-4 tracking and January deadlines yourself, see our payroll services or call us at (346) 389-5215.

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This article provides general information and is not tax advice. Payroll requirements and IRS withholding rules can change, and you should consult with a qualified tax professional about your specific situation.