Federal Withholding: The Employer's Guide
Federal withholding is money you hold in trust, not money you own. The threshold, the W-4 rules, and why an LLC will not protect you if you spend it.
Federal Withholding
The money in your account that was never yours, the threshold that makes a correct pay stub look broken, and the penalty your LLC will not stop
There is money sitting in your business bank account right now that is not yours.
It arrived there the moment you ran payroll. You calculated what each employee earned, you took the federal income tax out of it, and you paid them the rest. The part you took out is in your account, it looks exactly like every other dollar in there, and it belongs to somebody else.
That is the whole subject, and almost every explanation of federal withholding misses it, because they are written for the employee wondering what came out of their check. This one is written for you, and from your side the important fact is not the rate or the tables. It is that you are a custodian, and if you spend what you are holding, the consequences do not stop at the company. They follow you personally, past your LLC, through bankruptcy, for the full amount.
So: what federal withholding is, why a correct pay stub can show zero federal tax and still be right, what the W-4 does and what happens when you do not have one, and the penalty that founders running their own payroll almost never know exists until it is being assessed against them. I build FirstHR, which is not a payroll processor and does not deposit anything with the IRS. Your payroll provider does that. General information, not tax advice, and this touches an area where an accountant is a cheap purchase.
What Federal Withholding Is
Federal withholding is the federal income tax you take out of an employee's wages and send to the IRS on their behalf, in installments, across the year.
Read the last sentence again, because it is what separates this from every other line item in your accounts. Your rent is your money going out. Your matching FICA share is your money going out. The federal income tax you withheld is somebody else's money passing through, and the law treats it accordingly.
Payroll Withholding, and the System It Sits Inside
Payroll withholding is the wider practice of taking tax out of wages at source and paying it over, and federal income tax is one component of it. The others are the employee's Social Security and Medicare, and, in most places, state income tax plus whatever local tax applies where the employee actually works.
The payroll withholding system is what the country uses instead of asking wage earners to settle their income tax in one annual payment. The tax is collected as the money is earned, by the employer, pay period by pay period. Which is how an obligation that belongs to your employee ends up being enforced against you.
Worth marking the boundary of this article now: everything below is the federal income tax piece. State withholding is set state by state and the rules diverge considerably, which is a separate question by state and a separate set of registrations.
It Is Not Your Money
Worth being precise about which parts of a payroll run are yours and which are not, because the distinction has teeth.
The three red rows are trust fund taxes. The word is not decorative. Legally, from the moment you withheld that money, you have been holding property that belongs to the United States government, and the fact that it is commingled in your operating account with everything else does not change what it is.
Which produces a very specific and very dangerous cash flow trap. There is a month where things are tight. The money is sitting there. You think: I will pay the payroll taxes late, catch up next month, everybody does this. And you have just done the single thing this article exists to warn you about.
The Penalty That Follows You Home
Almost no founder running their own payroll knows this exists, and it is the most serious personal financial exposure in small business payroll.
Per the IRS guidance on employment taxes and the Trust Fund Recovery Penalty, a responsible person is anyone with the duty to perform and the power to direct the collecting, accounting, and paying of trust fund taxes. That is a test about actual control, not about titles, and it catches more people than owners.
But the word doing the most work is willfully, and it does not mean what a normal person would assume.
Sit with that one, because it inverts the instinct of every decent employer. In a tight month, you will want to pay your people first. That impulse is admirable and it is, in this specific and narrow context, the thing that creates the personal liability.
The Threshold, and the Zero
Now the question that brings most employers here, and the one where the honest answer is not a number.
People search for the threshold for federal tax withholding expecting a dollar figure, and there is not one. What there is instead is a mechanism, and understanding it explains a pay stub that looks broken.
Here is what is happening. The withholding tables build in the standard deduction. So when payroll calculates what to withhold for a part-time employee earning $480 a week, it is effectively projecting their annual income, comparing it against the point at which any federal income tax is actually due, and concluding correctly that none is. Zero withheld. The pay stub is right.
Meanwhile Social Security and Medicare came out in full, because they have no threshold whatsoever. Not a lower one. None. FICA applies from the first dollar an employee earns, and there is no income level at which it does not.
The exact wage at which income tax withholding begins depends on the employee's filing status and how often you pay them, which is why nobody can give you a single figure. What you can rely on is the shape of it: income tax has a floor and FICA does not, and the interaction of those two rules is what produces a pay stub that looks like a bug and is not one.
The same answer covers the question asked the other way round, as a minimum federal tax withholding. There is no minimum amount you are obliged to take out of a given paycheck. You withhold what the W-4 and the tables produce, and when that comes to nothing, nothing is the correct figure. What you may not do is pick a number of your own, or withhold zero because no form has arrived.
Withholding Is Not FICA
They come out of the same paycheck, they go to the same agency, and they behave almost nothing alike.
| Federal income tax withholding | FICA | |
|---|---|---|
| What it is | The employee's income tax, prepaid | Social Security and Medicare contributions |
| The rate | Varies by person. From their W-4 and the IRS tables | Fixed. 6.2 percent and 1.45 percent |
| Is there a threshold? | Yes. Below a certain wage, nothing is withheld | No. From the very first dollar |
| Do you match it? | No. Not a cent. It is entirely their tax | Yes. Dollar for dollar, from your own funds |
| Calculated on | Gross minus pre-tax deductions | The full gross. A 401(k) does not reduce it |
| Is it trust fund money? | Yes | The employee's half is. Your matching half is not |
The row about pre-tax deductions is the one that generates questions on the pay stub. A traditional 401(k) contribution reduces the base for income tax and does nothing at all to the FICA base. So an employee who increases their retirement contribution watches their federal withholding fall while their Social Security stays exactly where it was, which looks like an error and is entirely correct.
FIT on the Pay Stub: What the Abbreviation Means
FIT stands for federal income tax, and on a pay stub it is the subject of this whole article under a shorter name. FIT withheld is the amount you deducted from that check and are holding for the IRS. FIT taxable wages is the figure it was calculated from, and it is not the gross.
| What the stub says | What it stands for | What the number actually is |
|---|---|---|
| FIT, FED, FWT, or FITW | Federal income tax withheld | The employee's own income tax, deducted this period and held by you in trust. Varies person to person, driven by their W-4 |
| FIT taxable wages | The wages the income tax was calculated on | Gross pay minus pre-tax deductions such as a traditional 401(k) or a health premium under a Section 125 plan. Lower than gross whenever either exists |
| Gross pay | Everything earned before anything comes out | The starting point for both bases, but not itself either one. A 401(k) contribution comes out of the income tax base only; a Section 125 premium comes out of the FICA base too |
| SS, OASDI, or Fed OASDI/EE | Social Security | 6.2 percent of Social Security wages, from the first dollar, matched by you out of your own funds |
| MED or Fed MED/EE | Medicare | 1.45 percent of Medicare wages, also from the first dollar, also matched by you |
The gap between FIT taxable wages and gross is what generates the questions. An employee who raises their 401(k) contribution watches their FIT taxable wages drop below their gross while their Social Security wages stay at the full gross, because a 401(k) contribution reduces the income tax base and leaves the FICA base alone. A Section 125 health premium is the exception: it comes out of both bases, so it lowers the Social Security wages as well.
The other question is a FIT line reading $0.00 while everything else came out normally. That is the threshold doing exactly what it is built to do, not a fault in payroll. The lines that should never read zero are Social Security and Medicare, and if either of those is blank on a stub, something genuinely is wrong.
The W-4 Decides the Amount
Everything about how much you withhold from a given person comes from one form, and your job is to collect it, apply it, and keep it.
The collection is an onboarding problem rather than a payroll problem, and it belongs with the rest of the paperwork you gather before day one.
The last two questions in that list are the ones you cannot answer from memory, and both of them are answered by a single sheet. One row per employee, updated when a form arrives, plus a second tab holding the small number of people whose status expires or has been overridden by the IRS.
| A | B | C | D | E | F | G | H | I | J | K | L | M | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Employee | Start date | W-4 received on | Year printed on the form | Filing status as entered | Step 2 box checked | Step 3 dependent amount | Step 4 entries | Extra withholding per period | Claiming exempt | Where the signed form is stored | Keep until | Notes |
| 2 | Example: A. Novak | 2026-02-02 | 2026-01-28 | 2026 | Single | No | 0 | None | 0 | No | Employee record, tax folder | 2030-01-28 | Signed before the first run |
| 3 | |||||||||||||
| 4 | |||||||||||||
| 5 | |||||||||||||
| 6 | |||||||||||||
| 7 | |||||||||||||
| 8 | |||||||||||||
| 9 | Note | No form on file yet is still a row. Record the default you are withholding at and the date you last chased the form | |||||||||||
| 10 | Note | Keep until is at least four years after the form was completed and signed, and the test is whether you can produce it for one named person on request |
What Employers Must Do With Form W-4
The Form W-4 employer duty list is shorter than most people expect, and the useful part of it is what is not on there. Collect the form, apply the entries as written, retain it. Everything past those three things is either optional or off limits.
Start from the current blank. The IRS reissues Form W-4 for each tax year and publishes the PDF on its About Form W-4 page, which is where to pull it from rather than from the copy saved in your onboarding folder two years ago. A valid W-4 already on file for an existing employee stays valid; it is the blank you hand a new hire that needs to be this year's.
Applying the entries as written is the one employers improvise on. You are not required to audit them, and you do not quietly adjust one because it looks wrong to you, because the employee signs Step 5 under penalties of perjury and what is on the form is theirs to answer for. File the signed copy with the rest of the new hire paperwork and keep it afterwards with your payroll records, since IRS Publication 15 (Circular E), for use in 2026, lists copies of Forms W-4 among the employment tax records you hold for at least four years. You do not routinely send them to the IRS, although the IRS can direct you in writing to send specific ones.
Now the boundary, and it is the one employers cross without noticing. This one is not a rule the IRS enforces against you. It is a line you hold for your own protection: do not tell an employee what to put in Steps 1 through 5. Their correct withholding turns on facts you do not hold and have no business holding, such as a spouse's income, a second job, investment income, and what they plan to deduct.
Answer any of that and you are giving individual tax advice, on a form they signed and you did not. If the number then comes out wrong at filing time, you have handed a disappointed employee a reason to point at you rather than at their own entries, and you were never the person qualified to make the call.
The correct move is one sentence long. Send them to the IRS Tax Withholding Estimator, which Publication 15-T (2026) suggests employers recommend for multiple jobs, investment income, and part-year work, and tell them that anything past that is a question for their own tax preparer. Helpful, accurate, and none of it is your liability.
When There Is No W-4
The most common first-time employer mistake, and it comes from an entirely decent instinct: the form has not come back, so you wait.
The same default applies if they hand you a form that is invalid, and if you already hold an earlier valid W-4 for them, you keep withholding based on that one instead.
Exempt, and the February Deadline
An employee who had no federal income tax liability last year and expects none this year can claim exempt on their W-4, and you then withhold no federal income tax from their pay.
Two things about that which employers get wrong.
Exempt does not mean nothing comes out. It applies to income tax only. You still withhold Social Security and Medicare in full, from the first dollar, and you still pay your matching share. An employee who claims exempt expecting a clean paycheck is going to be disappointed, and telling them in advance costs you nothing.
Which means every February, in the middle of your year-end reporting, you have a second deadline that nobody sends you a reminder about, attached to a small number of employees you probably cannot name off the top of your head. Put it in the calendar in January.
When the IRS Overrides You
A situation most small employers have never heard of and will not expect: the IRS writes to you and tells you to ignore your employee's W-4.
It is called a lock-in letter. The IRS issues one where it identifies a serious under-withholding problem for a specific employee, and it specifies the withholding you must apply. Once it is in effect, you follow it.
The counterintuitive part is what happens next. Per the IRS guidance on withholding compliance, if the employee then gives you a revised W-4 that results in more withholding than the lock-in letter requires, you must honor it. If it results in less, you must ignore it and keep withholding per the letter.
So the rule is asymmetric and it is worth understanding rather than improvising: the employee can always ask you to withhold more. Once a lock-in letter exists, they cannot ask you to withhold less, and if they are unhappy about it, the person they need to speak to is the IRS rather than you.
How the Amount Is Calculated
You are not going to do this by hand, and you should not try. But you should understand what the software is doing, because the software is only as right as what you fed it.
And note that bonuses do not follow this path. Supplemental wages may be withheld at a flat rate rather than through the tables, which is why an employee receiving a bonus sees a withholding percentage that looks nothing like their usual one and concludes they were penalized for good work. They were not.
Federal Withholding Tables: How to Read Them
The federal withholding tables are not a rate card you can memorize. They live in IRS Publication 15-T, which sets out two main routes to a number: the percentage method, which calculates from an annualized taxable wage, and the wage bracket method, which reads a figure straight out of a grid.
They come from the IRS and from nowhere else, and they are reissued for every tax year because the bracket boundaries are inflation adjusted. The edition current as I write this is Publication 15-T (2026), Federal Income Tax Withholding Methods. Same worksheets each year, different numbers inside the rows.
Take the wage bracket method first, because it is the one written for people doing this without software. You adjust the period wage for the other income and the deductions entered in Steps 4(a) and 4(b) of their W-4, open the grid for your pay frequency, find the row, and read across. The withholding amount is printed in the cell rather than calculated.
The row is where people go wrong. Each row covers a span, printed as at least one amount and less than the next, so your wage falls inside a band rather than matching a line. Then you read across to the column for their filing status and for whether the Step 2 box on their W-4 is checked.
It has a ceiling. Per Publication 15-T (2026), the wage bracket tables cover a limited amount of annual wages, generally less than $100,000, and if taxable wages run past the last bracket for that filing status and pay period, you have to abandon the grid and use the percentage method instead.
The percentage method has no such ceiling, and that is the whole reason it exists. Worksheet 1A annualizes the period wage, subtracts a fixed amount, lands the result in a row of an annual rate schedule, applies a base dollar figure plus a percentage of the excess over the bottom of that row, then divides the year back into paychecks.
So, plainly: a small employer running payroll by hand uses the wage bracket method, which is exactly what it was published for. Payroll software uses the percentage method regardless, for every employee, because it works at any wage level and against a Form W-4 from any year.
Here is that percentage method run end to end on one person: single, a W-4 from 2020 or later with the Step 2 box unchecked and nothing entered in Steps 3 or 4, paid biweekly.
One detail in that ladder explains the zero from earlier in this article. The single schedule charges nothing until the adjusted annual wage clears $7,500, and the worksheet has already taken $8,600 off. Add those and you get $16,100, which is the standard deduction for a single filer for tax year 2026 under the IRS inflation adjustments in Rev. Proc. 2025-32.
That is the deduction being built into the tables, and the married filing jointly rows do the same thing with $19,300 and $12,900. Nobody is applying a deduction later. It is already sitting inside the row you looked up, which is why a low earner reaches the bottom band and withholds nothing.
Now the part that quietly goes wrong. The payroll withholding tables are reissued for each tax year and the rows move, so running January payroll off last year's copy makes every check wrong by a small amount, in the same direction, for as long as nobody notices.
Nothing in your process flags that. It surfaces at year end, when the W-2 reports withholding that does not line up with what the employee actually owed, and you cannot go back and re-withhold wages you already paid. They settle the difference on their return and then ask you about it.
Depositing Is Not Filing
Two separate obligations, two separate schedules, two separate penalties, and confusing them is one of the most reliable ways to be punished for something you thought you had done.
| Depositing | Filing | |
|---|---|---|
| What it is | Sending the money to the IRS | Reporting what happened, on Form 941 |
| How often | On a schedule the IRS assigns you. Monthly for most small employers | Quarterly |
| Driven by | Your prior tax liability, not your choice | The calendar |
| Miss it and | A failure-to-deposit penalty, tiered by how late | A failure-to-file penalty, separate and additional |
| The trap | It is due long before the return is | Filing on time does not fix a late deposit |
The consequence is that a business can file its 941 perfectly on time, every quarter, and still be accruing penalties, because the deposits behind it were late. Which is why payroll feels finished when the employees have been paid and is not finished until the government has been paid too.
Common Mistakes
The thread running through the serious ones is a single misunderstanding of what kind of money this is. Every other obligation in your business is a debt: something you owe, which can be negotiated, deferred, and in the worst case discharged along with the company.
Withheld tax is not a debt. It is property you are holding. And the law's response to somebody who spends property they were holding in trust is categorically different from its response to somebody who cannot pay their bills, which is why this one liability reaches through the entity, through the bankruptcy, and into your own bank account.
Frequently Asked Questions
What is federal withholding?
Federal withholding is the federal income tax an employer deducts from an employee's wages and pays over to the IRS on their behalf. It is a prepayment of the employee's eventual annual tax bill, collected gradually across the year rather than in one lump at filing. The critical thing for an employer to understand is that the money is not yours at any point. It belonged to your employee, you removed it from their pay on the government's behalf, and you are holding it in trust until you deposit it.
What is federal withholding tax?
The same thing, and the terms federal withholding, federal tax withholding, federal withholding tax, and fed withholding all refer to it. It is the federal income tax deducted from wages at source. Withholding tax as a broader term can also cover other situations where tax is deducted before payment reaches the recipient, but in a payroll context it means the federal income tax you take out of your employees' paychecks and remit to the IRS.
What is the threshold for federal tax withholding?
There is no single dollar figure, and the answer surprises people. Federal income tax withholding is calculated from the employee's Form W-4 and the IRS withholding tables, and those tables build in the standard deduction. The practical effect is that an employee earning below a certain amount for the pay period has no federal income tax withheld at all, because their projected annual income falls below the point at which any tax is due. The exact figure depends on their filing status and pay frequency rather than being a fixed number.
Why is no federal tax being withheld from my employee's paycheck?
Most likely because they earn too little for any to be due, and payroll is working correctly. Federal income tax withholding is calculated against tables that account for the standard deduction, so a part-time or low-wage employee can legitimately show $0.00 withheld. The other possibilities are that they claimed exempt on their W-4, or that their W-4 has entries reducing their withholding. What should never be zero is FICA, because Social Security and Medicare have no threshold and are withheld from the very first dollar.
What is the difference between federal withholding and FICA?
They are two different taxes with different rules and it is worth keeping them straight. Federal income tax withholding is the employee's income tax, calculated from their W-4, varying by person, with a threshold below which nothing is withheld, and no employer match. FICA is Social Security and Medicare, at fixed rates of 6.2 and 1.45 percent, with no threshold at all, applying from the first dollar, and matched by you dollar for dollar. Both are withheld from the same paycheck and they behave almost nothing alike.
Do I match federal income tax withholding?
No. You match FICA, meaning Social Security and Medicare, dollar for dollar out of your own funds. You do not match federal income tax withholding at all. That tax is the employee's alone; you are simply the collection mechanism. It is a useful distinction to hold onto because it maps exactly onto the trust fund question: the income tax you withheld is entirely their money held by you, whereas your matching FICA share is genuinely your own business expense.
What happens if I do not deposit the federal withholding I collected?
This is the most dangerous thing you can do in payroll and it does not stay inside the business. Withheld income tax and the employee's share of FICA are trust fund money. Under the Trust Fund Recovery Penalty, a responsible person who willfully fails to pay it over can be held personally liable for 100 percent of the unpaid amount, plus interest. Your LLC does not protect you, because the assessment runs against you as an individual rather than against the company, and it generally survives bankruptcy.
What counts as willful for the Trust Fund Recovery Penalty?
Far less than the word suggests, and this is what catches honest people. It does not require dishonesty or an intent to defraud anybody. Using available funds to pay any other creditor instead of the withheld taxes is treated as willfulness. That includes paying your employees their net wages. If you do not have enough money to cover both the wages and the taxes withheld from them, an employee owed wages is treated as simply another creditor, and preferring them to the government is exactly the conduct the penalty exists to punish.
Can the IRS come after me personally if my business is an LLC?
For trust fund taxes, yes. The Trust Fund Recovery Penalty is assessed against the individual rather than against the entity, which means there is no corporate veil for it to pierce, because it never went near the entity in the first place. An LLC, an S corporation, and a C corporation all leave you exposed on this specific liability. It is one of the few situations where the structure you chose to protect your personal assets simply does not apply.
Who is a responsible person for the Trust Fund Recovery Penalty?
Anyone with the duty and the authority to collect, account for, and pay over the taxes, and it is defined by actual control rather than by job title. Courts look at who signed the checks, who decided which creditors got paid, who had hiring and firing authority, and who was involved in the day-to-day finances. Owners are the obvious target, but bookkeepers, office managers, and controllers have all been held personally liable in real cases. Being instructed by a superior not to pay the taxes does not relieve you if you were otherwise responsible.
What if an employee does not give me a W-4?
You still withhold, and you withhold at the highest standard rate. The IRS is explicit: an employee who fails to furnish a Form W-4 is treated as if they had checked single or married filing separately and made no other entries on the form. Withholding nothing because you lack the paperwork is not a neutral act of patience; it is a failure to withhold, and the liability for that lands on you rather than on the person who did not do their forms. Keep chasing the form, but do not wait for it.
How long do I have to keep a W-4?
At least four years after it is completed and signed, which is longer than the general three-year floor for payroll records and does not line up neatly with anything else. The form is your evidence that you withheld according to the employee's instructions, and it has to be available if the IRS asks. Which means a W-4 that exists somewhere in an email thread is not really being retained; the test is whether you can produce it, for a specific person, several years after they filled it in.
Can an employee claim exempt from federal withholding?
Yes, if they had no federal income tax liability last year and expect none this year. If they claim exempt on their W-4, you withhold no federal income tax from their pay. But note carefully what exempt does not cover: it applies only to income tax. You still withhold Social Security and Medicare in full, and you still pay your matching share. An employee who thinks claiming exempt means nothing comes out of their check is going to be disappointed, and you can save yourself the conversation by saying so.
Does an exempt W-4 need to be renewed?
Yes, every year, and this is the deadline employers miss. An exempt W-4 is only valid for the calendar year in which it was furnished. To stay exempt the following year the employee must give you a new W-4 claiming exempt by February 15. If they do not, you must begin withholding as if they were single with no other entries. And if they hand you a new exempt form after that date, you may apply it going forward but you do not refund the tax you withheld while the exemption was not in place.
What is a lock-in letter?
A notice from the IRS instructing you to withhold at a specified rate for a particular employee, overriding whatever their W-4 says. The IRS issues them where it identifies a serious under-withholding problem, and once one is in effect you must follow it. The counterintuitive part is what happens if the employee then submits a new W-4: if it produces more withholding than the lock-in letter requires, you honor it; if it produces less, you ignore it and follow the letter. The employee's remedy is with the IRS, not with you.
How do I calculate federal withholding?
Using the employee's W-4 and the withholding methods in IRS Publication 15-T, which sets out both a wage bracket method and a percentage method. In practice you will not do this by hand, because any payroll system does it for you and does it correctly. What matters is that the inputs are right: the correct filing status, the correct entries from the W-4, the correct pay frequency, and the correct gross wages. The arithmetic is the software's job. The inputs are yours.
What is the difference between depositing and filing?
They are separate obligations on separate schedules and confusing them is a standard route to a penalty. Depositing is sending the money, and it happens on a schedule the IRS assigns you based on your prior tax liability, which for most small employers is monthly. Filing is reporting what happened, on Form 941, quarterly. You can file the return perfectly on time and still owe a penalty because your deposits were late, and depositing does not relieve you of the requirement to file.
How is a bonus withheld?
Differently, and the employee will notice. Bonuses and commissions are supplemental wages, and federal income tax may be withheld on them at a flat rate rather than through the ordinary tables. So an employee receiving a bonus sees a withholding percentage that looks nothing like their usual one and concludes they were punished for good work. They were not; it is a withholding convention and it settles up when they file. But you will be asked, so it is worth being able to explain it in one sentence.
Does federal withholding come out of gross pay or taxable wages?
Taxable wages, which is gross pay minus pre-tax deductions. A traditional 401(k) contribution and a health premium running through a Section 125 plan both reduce the base on which federal income tax is calculated. This is where employers get confused, because FICA does not work that way: Social Security and Medicare are calculated on the full gross, ignoring the 401(k) entirely. So the two taxes on the same paycheck are calculated against two different figures, deliberately.
Do I withhold federal tax from contractors?
No. Federal income tax withholding applies to employees, not to independent contractors. A contractor is paid the full amount, handles their own tax through estimated payments, and receives a Form 1099-NEC at year end rather than a W-2. Which makes worker classification a much more serious question than a paperwork one: if a contractor is reclassified as an employee, you owe the withholding you never took, plus the FICA you never matched, plus penalties, for the entire period.