Payroll Tax vs Income Tax: What Employers Pay

Every guide to this topic answers the wrong question. They explain that payroll taxes fund social insurance while income taxes fund general spending, that one is flat and the other progressive, and they are correct, and none of it tells you the thing you actually need to know.

Here is the thing you actually need to know: income tax costs your business nothing. Not a dollar. It is the largest line on your employee's pay stub, you calculate it, you withhold it, you remit it, you are liable if you get it wrong, and it is not your money and it never was. You are a courier.

Payroll tax is different, and the difference is not conceptual. Part of it comes out of your account. When your employee pays $100 in Social Security, you pay another $100, out of business funds, and it never appears on their pay stub, and they do not know it happened.

So the useful axis is not payroll versus income. It is what you pay versus what you merely handle, and once you see it that way the whole subject collapses into something you can budget around. This guide covers both, in the detail an employer needs: every rate, every cap, every form, what a hire actually costs in tax, and why classifying someone as a contractor saves you roughly a tenth of their pay. It is written for a US business with five to fifty people and no HR department. FirstHR is not a payroll processor and does not file your taxes; your provider does that. What I build is the layer around it. This is general information rather than tax advice, rates change annually, and you should verify the current year's figures with your accountant rather than with a blog post.

The Short Answer

If you take one thing from this article, take this table. Everything else is elaboration.

Look at the second row. It is the entire article, and it is the row nobody leads with. Everything else here is elaboration on that one asymmetry, and it is the asymmetry that decides what you can afford to pay someone, which makes it a small business question rather than an accounting one.

Pay vs Withhold, the Distinction That Actually Matters

Forget the payroll and income labels for a moment. Sort the money by whose it is.

Now look at what that reorganization reveals. The employee's share of Social Security and Medicare is in the right column, alongside income tax, because although it is a payroll tax, it is the employee's money and you are only forwarding it. And the Additional Medicare Tax sits there too, despite being a Medicare levy, because you withhold it and do not match it.

Which means the payroll-versus-income distinction, the one every article is built around, does not actually align with the distinction that determines your costs. Some payroll tax is your money. Some payroll tax is not. And none of the income tax ever is.

What Payroll Tax Is

Payroll taxes are levied on wages, at flat rates, to fund specific programs. That is the whole definition and it explains their behaviour.

Three properties follow from that definition and they are worth naming.

Flat. Social Security is 6.2 percent whether the employee earns $30,000 or $150,000. There are no brackets. The only nonlinearity is the wage base, which is a cap rather than a bracket, and the Additional Medicare Tax, which is a surcharge rather than a progression.

Earmarked. The money is not general revenue. Social Security tax funds Social Security. Medicare tax funds Medicare. FUTA and SUTA fund unemployment insurance. This is why they are sometimes called social insurance contributions rather than taxes, and it is why they exist as separate lines rather than being folded into income tax.

Shared. This is the property that costs you money, and it is the one that most owners underweight until they are budgeting a hire. It belongs in your HR processes as a standing line rather than an annual surprise.

What Income Tax Is

Income tax is levied on a person's income, progressively, and funds general government spending. And from your point of view as an employer, the important word is person.

Because it is a tax on the person, it depends on facts about the person that have nothing to do with you: their filing status, their dependents, their spouse's income, their other income, their deductions. You cannot know most of that, which is why the whole system runs off a form the employee fills in themselves.

Withholding is an estimate, not a settlement

Worth understanding because employees ask. The income tax you withhold is a prepayment, calculated from the W-4, of a liability that will only be finally determined when they file their return. If you withheld too much, they get a refund. If too little, they owe.

Neither outcome means your payroll was wrong. And neither is your problem: your obligation is to withhold the amount the W-4 and the IRS tables produce, not the amount that turns out to be correct at year end. The same logic explains why a bonus appears to be taxed punitively when it is only being withheld at a different rate, which is set out in the supplemental pay guide.

The W-4 is the whole mechanism

Everything about income tax withholding flows from that one form. Get it during onboarding, keep it, act on it, and update it when they give you a new one. It sits alongside the rest of the tax forms for new employees, and it is the single most consequential piece of paper in the stack for this purpose.

One thing you should not do is advise an employee on how to fill it in. You are not their tax adviser, you may be creating liability for yourself, and the IRS publishes its own estimator. Point them at it and step back. Collect the form during onboarding, file it properly, and act on whatever it says.

Every Employment Tax in One Table

The complete picture. Rates and thresholds change annually; the structure does not.

Two rows in that table are structurally strange and both are worth their own section. Additional Medicare is a payroll tax with no employer share, which makes it behave like an income tax wearing a payroll tax's clothing. And SUTA is the only employment tax whose rate is specific to you personally rather than set by statute. Whether a given worker is exempt or nonexempt does not change any of it, incidentally, which is a separate question covered in the exempt versus non-exempt guide.

FICA in Detail

FICA is where most of the money is, and it is where the employer match lives.

Per IRS Topic 751, the rates are as above, and the Social Security wage base is adjusted each year. The employee's combined FICA is 7.65 percent, and yours is the same 7.65 percent, out of your own funds.

The wage base, and the autumn surprise

Social Security stops at the annual wage base. Once an employee's year-to-date wages cross it, the deduction disappears from their stub and their net pay rises.

Two consequences. First, they will ask you about it, having concluded that payroll made an error in their favour. Second, and more usefully, your matching contribution stops at the same moment, so your cost for that employee drops for the rest of the year and resets in January. If you employ several people near the wage base, that produces a genuinely lumpy tax expense across the year, and it is worth modelling rather than discovering.

Medicare, by contrast, never stops. It is 1.45 percent on the first dollar and the millionth. Both lines are visible on the employee's pay stub, which is where they will notice the change and where they will come to you about it.

The Additional Medicare Tax, and Why It Breaks the Categories

This is the tax that shows the payroll-versus-income distinction is not as clean as everyone pretends.

Look at what that is. It is levied under the Medicare rules, appears on Form 941 with the other payroll taxes, and is described as a payroll tax by everyone. But it is paid entirely by the employee, is triggered by an income threshold, and depends on the employee's overall tax situation, since the actual liability threshold varies with filing status.

That is an income tax in every respect except its name and its filing location.

The wrinkle that catches employers

You withhold based on wages you paid, at $200,000, without regard to filing status. But the employee's actual liability depends on their filing status and their household income, which may include a spouse's wages from a different employer.

So an employee may end up owing more than you withheld, or less. Both happen, and both are resolved on their tax return. Your obligation is discharged by withholding on the wages you paid once they crossed $200,000, and that is the beginning and end of your responsibility here. It is a good example of why the boundary between employment law and tax law is less tidy than it looks.

FUTA and SUTA, the Taxes You Pay Alone

The unemployment taxes are pure employer cost. Nothing is withheld from the employee, in almost every state, and the whole thing comes out of your account.

FUTA

Per IRS Topic 759, the FUTA rate is 6.0 percent on the first $7,000 of each employee's wages. But employers who pay their state unemployment taxes in full and on time receive a credit of up to 5.4 percent, dropping the effective rate to 0.6 percent.

Forty-two dollars a year. It is genuinely small, and the reason to know about it anyway is the exception.

SUTA

State unemployment tax is the strange one, because your rate is personal to you.

States assign an experience rating based on your history of unemployment claims. Lay people off, and former employees claim benefits, and your rate goes up. Do not, and it goes down. New employers start at a standard rate until they have a history.

Which produces a fact worth internalizing: firing people is more expensive than it looks, and the extra cost is spread invisibly across your SUTA rate for years afterwards. It is not a large amount, but it is real, and it is the only tax in this entire article that responds to how you actually run the business. Add it to the other costs of a departure, including any PTO payout you owe.

SUTA is also the one place where employees sometimes contribute. In most states they do not, but in a small number, including Alaska, New Jersey, and Pennsylvania, employees pay a share of state unemployment tax too.

What a Hire Really Costs You in Tax

Here is where all of this becomes a number you can put in a budget.

Roughly 8 to 11 percent above salary, in tax alone, before any benefit, before workers compensation, before equipment. If you are budgeting a hire at their salary figure, you are budgeting wrong by about a tenth.

And the thing to notice, having read this far: no income tax appears in that table at all. The largest deduction on your employee's pay stub, the one they complain about, the one that takes the biggest bite out of their gross, is invisible to your cost structure. It passes through you and touches nothing. The wider cost picture, including benefits, sits in the guide to how much benefits cost per employee.

The Forms You File

Four forms carry the whole thing, and they split neatly along the lines this article has been drawing.

Notice that Form 941 mixes the two categories: the income tax you merely withheld sits on the same return as the FICA you actually paid. Which is a small piece of evidence for the thesis of this article, that the payroll and income labels do not carve the world at its joints, but the pay-versus-withhold distinction does.

Form 940, by contrast, is pure employer cost. There is no employee column, because there is no employee contribution. Keep the filings with your other records, to the standards in the guide on how long to keep employee records.

Deposits, Deadlines, and the One That Can Ruin You

Filing is not the same as paying. You deposit the money throughout the year and file a return summarizing it, and the deposits are where the danger is.

Your deposit schedule, monthly or semiweekly, is determined by your total tax liability in a lookback period, and it keys off your pay dates rather than the periods worked, a point covered in detail in the arrears guide.

This is the single most dangerous thing in payroll, and it comes directly from the pay-versus-withhold distinction. The money you withheld was never yours to spend. Spending it is not a cash flow decision. It is a decision to use somebody else's money, and the government takes that view of it too. The deposit timing rules that govern it are covered alongside direct deposit, because both key off your pay date.

If You Pay Yourself

Founders ask this and the answer depends entirely on structure.

The self-employment tax rate is 15.3 percent, which is exactly the combined employee and employer FICA, because that is what it is. You can deduct the employer-equivalent half when computing income tax, which reduces the pain without removing it.

The S corp salary-versus-distribution question is a genuine planning area and a genuine audit risk, and it is beyond the scope of anything you should decide from an article. Take advice, and note that setting your own pay schedule is a separate decision from setting your own salary.

Contractors Change Everything, Which Is the Problem

If the person is a 1099 contractor rather than a W-2 employee, your entire tax obligation vanishes.

Read the last row and you will understand why worker classification is enforced as aggressively as it is. Calling someone a contractor rather than an employee saves you around a tenth of what you pay them, plus benefits, plus workers compensation, plus a set of legal obligations.

How It All Looks on a Pay Stub

Everything in this article lands, eventually, on a document your employee reads and misunderstands. Here is the translation.

The last row is the point. Your half of the tax is invisible. The pay stub is a statement of the employee's wages, not a statement of your costs, so the 7.65 percent you paid to match them appears nowhere, and neither does the unemployment tax.

Which means an employee looking at their stub has no way of knowing what you actually spend on them, and an employer who wants them to know has to tell them separately. The full anatomy of the document is in the pay stub guide, and the timing of when it lands is explained in the arrears guide.

Common Mistakes

These recur, and the last one is in a different league from the others.

The unifying error is treating the money in your payroll account as though it is all yours. Some of it is. Most of it is not. The portion you withheld belongs to your employee and to the government, you are holding it in trust, and the entire structure of penalties around payroll tax exists because that distinction is easy to blur when cash is tight. The rest of the recurring small-employer errors are collected in the HR rules and regulations guide.

Frequently Asked Questions