What Is Payroll? Functions, Calculations, and Processing

Ever wondered how many laws you touch in a single pay run?

Payroll is how a business pays its people. It calculates wages, withholds taxes and other deductions, releases net pay, and files the returns that prove the whole thing was done correctly. When it works, nobody notices. When it does not, you deal with upset employees and a penalty notice in the same week.

This guide covers what payroll is, what employers are legally on the hook for, how the numbers are worked out using current 2026 rates, and how to choose a processing method that fits your size. For a breakdown of the individual pay elements, start with payroll components.

What is payroll?

Payroll has two meanings that people mix up constantly. As a noun, it is the list of everyone a company pays and what each person earns. As a process, it is the recurring work of turning that list into accurate payments and filings for a given pay period. Both meanings are correct, and most conversations about payroll slide between them.

Whatever the size of the business, every pay run does the same five things:

• Collects the data: hours worked, approved overtime, leave taken, pay changes, joiners and leavers.
• Calculates gross pay from salaries, hourly rates, commissions, bonuses and any other earnings.
• Applies deductions in order: pre-tax items first, then taxes, then post-tax items.
• Pays employees the resulting net amount by direct deposit, check or pay card.
• Remits and reports: sends withheld tax and employer contributions to the right agencies and files the required returns.

Those five steps are the backbone of every payroll system, whether it runs on a spreadsheet or on enterprise software.

Payroll sits right next to HR without being the same function, and the split matters when you are deciding who owns what. (Read: payroll vs HR)

What is the payroll process, step by step?

A pay run follows the same sequence every cycle. Here is what it looks like from timesheet cut-off to filing:

1. Close the pay period and lock timesheets, so late edits cannot change numbers you have already checked.
2. Verify employee data: pay rates, withholding elections, bank details and benefit elections.
3. Calculate gross pay for each person, including overtime, shift differentials, commissions and bonuses.
4. Apply pre-tax deductions such as health premiums and traditional retirement contributions.
5. Withhold federal, state and local income tax, plus Social Security and Medicare.
6. Apply post-tax deductions such as garnishments, Roth contributions and union dues.
7. Fund and release the payments, then issue pay stubs.
8. Deposit the taxes and file the returns by their due dates.

Change the order and the arithmetic quietly breaks, because a pre-tax item applied after withholding overstates the tax you take. Written down as a checklist, this sequence is also the fastest way to hand payroll over to someone else.

(See: payroll administration)

What are an employer's payroll responsibilities?

The legal obligation for almost every part of payroll sits with the employer, not the employee and not the software vendor. Five duties come up every single cycle.

Paying wages and benefits correctly

You owe each employee the pay set out in their offer letter or contract, at the frequency their state requires, including overtime, bonuses, commissions and any accrued leave payout. Benefit deductions such as health premiums and retirement contributions have to be applied correctly and forwarded to the plan on schedule.

Withholding and depositing taxes

You withhold federal income tax, Social Security, Medicare and any applicable state and local taxes from each paycheck, add the employer share on top, and deposit the total on the schedule you have been assigned. The IRS sets these rules out for employers in Publication 15, the Employer's Tax Guide.

Filing returns and reports

Returns exist to prove your deposits match what you withheld. Most US employers file Form 941 each quarter, Form 940 once a year for federal unemployment tax, and Forms W-2 and W-3 after year end. Until each of those amounts leaves your account it sits on your books as an obligation. (Read: payroll liabilities)

Keeping records

The Fair Labor Standards Act requires payroll records to be kept for at least three years, and the records used to compute pay, such as time cards and wage-rate tables, for two years. The IRS wants employment tax records kept for at least four years after the tax is due or paid. Keeping everything for four years is simpler than tracking two clocks.

What employees are responsible for

Employees complete Form W-4 so you know how much federal income tax to withhold, and they have to tell you when their name, address, bank details or withholding choices change. One point worth correcting, because outdated guides still repeat it: the W-4 no longer uses withholding allowances. Since the 2020 redesign it asks about dependents, other income and deductions instead, which is why the current Form W-4 looks nothing like the version most people remember.

How do you calculate payroll?

Payroll maths runs in one direction: gross pay, then deductions, then net pay. The formulas are simple. What changes every year are the rates, the wage caps and the thresholds sitting behind them.

(See: payroll deductions)

Three formulas cover most of the work:

• Gross wages = hourly rate × hours worked, or annual salary ÷ number of pay periods
• Overtime pay = regular hourly rate × 1.5 × overtime hours
• Net pay = gross wages - total deductions

Everything else is a question of which rate applies and in what sequence. The figure the employee actually cares about is the last one.

(Read: net pay)

Two of those numbers moved for 2026. The Social Security wage base rose from $176,100 to $184,500, which caps the employee Social Security tax at $11,439 for the year. Most employers still pay a net FUTA rate of 0.6%, or about $42 per employee per year, because the full 5.4% state credit applies. That credit shrinks in states carrying outstanding federal unemployment loans, so check the current FUTA credit reduction list before you budget.

The full employer side is set out in our guide to employer payroll taxes.

Worked example: a salaried employee

Take someone on $52,000 a year paid biweekly, with a $200 pre-tax health premium, $250 of federal withholding and $100 of state withholding per period.

• Gross pay per period: $52,000 ÷ 26 = $2,000
• Wages subject to FICA after the pre-tax premium: $2,000 - $200 = $1,800
• Social Security: $1,800 × 6.2% = $111.60
• Medicare: $1,800 × 1.45% = $26.10
• Total deductions: $200 + $250 + $100 + $111.60 + $26.10 = $687.70
• Net pay: $2,000 - $687.70 = $1,312.30

Note where the health premium sits. Under a Section 125 plan it comes off before FICA is calculated, not after, so running FICA on the full $2,000 would overcharge both the employee and you. That single sequencing mistake is one of the most common errors in manual payroll.

Worked example: an hourly employee

Now an hourly employee at $15 an hour who works 40 regular hours plus 5 overtime hours, with a $100 pre-tax health premium, $50 federal and $30 state withholding.

• Regular pay: $15 × 40 = $600
• Overtime pay: $15 × 1.5 × 5 = $112.50
• Gross wages: $600 + $112.50 = $712.50
• Wages subject to FICA: $712.50 - $100 = $612.50
• Social Security: $612.50 × 6.2% = $37.98
• Medicare: $612.50 × 1.45% = $8.88
• Total deductions: $100 + $50 + $30 + $37.98 + $8.88 = $226.86
• Net pay: $712.50 - $226.86 = $485.64

Both examples are simplified. Real runs also carry state disability contributions, local levies, retirement matches and any court-ordered withholding. Overtime in particular gets complicated once shift premiums or non-discretionary bonuses enter the regular rate.

(See: how to calculate overtime pay)

Pre-tax versus post-tax deductions

Pre-tax deductions come off gross pay before tax is calculated and reduce taxable wages: health, dental and vision premiums under a Section 125 plan, HSA and FSA contributions, and traditional 401(k) deferrals. Post-tax deductions come out of net pay and change nothing about tax: Roth contributions, union dues and charitable giving.

(Read: post-tax deductions)

Court-ordered withholding is the exception that needs its own handling, because the amount is capped by law and takes priority over voluntary deductions.

(See: wage garnishment)

What payroll taxes and filing deadlines apply?

Withholding the money is only half the job. Depositing and filing it on time is the half that generates penalties. Your deposit schedule is either monthly or semiweekly, and the IRS assigns it based on the tax you reported during a four-quarter lookback period. One rule overrides both: if your accumulated liability ever reaches $100,000, that amount is due by the next business day. The mechanics are set out in the IRS guidance on depositing and reporting employment taxes.

The tiers replace each other rather than stacking, so a deposit 20 days late attracts 10%, not 17%. Interest runs on top of the penalty. Full detail sits in the IRS page on the failure to deposit penalty.

One rule catches smaller employers out: if you file 10 or more information returns of any type in a year, they all have to be filed electronically. It also helps to be clear that the tax you withhold on the employee's behalf and the tax you owe as the employer are two separate liabilities.

(Read: payroll tax vs income tax)

How does worker classification affect payroll?

Classification decides whether someone goes through payroll at all. Employees receive wages with tax withheld, employer FICA on top and benefit eligibility. Independent contractors invoice you, handle their own tax, and receive a 1099-NEC instead of a W-2.

The line is drawn on control and independence, not on what the contract calls the relationship. If you set the hours, supply the tools and direct how the work is done, you are probably looking at an employee whatever the paperwork says.

(See: independent contractor vs employee)

Getting it wrong is expensive: back taxes, unpaid overtime, penalties and interest, usually applied to everyone in the same role rather than only the person who raised it.

(Read: employee classification)

Contractors still need tracking, just outside the payroll run: contracts, W-9s on file, and 1099-NECs issued at year end.

(See: 1099 contractor)

How do you run payroll for remote and multi-state employees?

Remote work turned a single-state payroll problem into a multi-state one for a lot of employers. Where the employee physically works usually decides which state's income tax, unemployment insurance, minimum wage, overtime rules and pay-frequency laws apply. Where your office is registered rarely matters.

Four things to sort out before a remote hire is paid for the first time:

• Register with the tax and unemployment agencies in the employee's state ahead of the first pay run, not after it.
• Check whether a reciprocity agreement lets you withhold for the employee's home state instead of the work state.
• Apply the higher of the federal, state and local minimum wage, and the stricter of the overtime rules.
• Match pay frequency and pay stub content to the employee's state, since both are regulated locally.

Do this once per state and it becomes routine. Skip it and you get notices from agencies you did not know you were registered with.

(See: state tax reciprocity agreements)

Crossing a border rather than a state line adds employment law, currency, statutory benefits and a local filing calendar to the same list.

(Read: global payroll)

What payroll regulations must employers follow?

The Fair Labor Standards Act

The FLSA sets the federal minimum wage at $7.25 an hour, requires overtime at 1.5 times the regular rate beyond 40 hours in a workweek, and sets the recordkeeping and child labor standards. Many states set a higher minimum, and the higher figure governs.

The exempt salary threshold is the piece most guides still have wrong, and it is worth checking against your own job descriptions. A 2024 rule that would have taken it to $58,656 was vacated in court, and in May 2026 the Department of Labor issued a technical amendment formally restoring the earlier level of $684 a week, or $35,568 a year, along with $107,432 for the highly compensated employee exemption.

Several states sit above that, and the DOL keeps the current salary levels published. Salary alone is not enough either, because the duties test has to be met as well.

FICA and FUTA

FICA funds Social Security and Medicare and is split evenly between employee and employer at 7.65% each. FUTA funds unemployment benefits and is paid by the employer only. The one asymmetric piece is the Additional Medicare Tax of 0.9% above $200,000 in wages, which you withhold from the employee but do not match.

State and local rules

States set their own minimum wage, overtime rules, pay frequency, final paycheck timing, paid sick leave and pay stub requirements, and some cities add their own on top. Pay frequency in particular is a legal question before it is an operational one, because several states mandate a minimum frequency for certain worker types.

(See: pay cycle types)

Biweekly is the most common cycle in the US at 26 runs a year, against 52 weekly, 24 semimonthly and 12 monthly. The two months a year that carry three biweekly pay dates need planning for cash flow and for deduction caps.

(Read: how many paychecks in a year biweekly)

Audits and data protection

Run an internal payroll check each quarter rather than waiting for an audit notice, and keep access to payroll data limited to the people who genuinely need it. Payroll files hold Social Security numbers, bank details and salary history, which makes them one of the most attractive targets in the business. Where you handle employee data across borders, data protection law travels with the data, not with your head office.

"Payroll compliance is no longer just an HR or payroll function issue. With wage underpayments now carrying potential criminal consequences, governance, oversight and effective controls have become more important than ever." Craig Philp, on LinkedIn

How does payroll processing work?

There are three ways to get payroll done, and the right answer usually changes as headcount grows.

Most businesses start in-house because it looks free, then move once the hours spent and the risk carried stop being invisible.

(See: in-house payroll vs outsourcing)

How long a run takes depends less on headcount than on how clean the inputs are. Late timesheets, manual approvals and stale employee records stretch a two-hour job into two days.

(Read: automated payroll system)

How do you choose a payroll system or provider?

Whichever route you take, the same six checks apply. Score candidates against them before you sit through a demo, not after:

• Coverage: every state, and every country, where you actually have people today.
• Tax handling: does the provider calculate, deposit and file, or only calculate and leave the rest to you?
• Integrations: time tracking, HR system and accounting ledger, so data gets entered once.
• Self-service: pay stubs, W-2s and withholding changes without a support ticket.
• Security: encryption, role-based access and a current SOC 2 report you can actually read.
• Pricing: the per employee per month figure, plus a clear list of what counts as an add-on.

Those six turn a vague vendor comparison into a scoreable one, and they surface the gaps that only appear in month three.

(See: how to choose a payroll provider)

Smaller employers usually want tax filing bundled in rather than sold separately, since that is the part that carries the penalty risk.

(Read: payroll services for small business)

A PEO co-employs your staff and takes on payroll, tax filing, HR administration and benefits, which works well when you have your own entity but not your own HR bench.

(See: PEO)

An Employer of Record goes further and becomes the legal employer, which is the route to take when you want to hire somewhere you have no entity at all.

(Read: Employer of Record)

How can you optimize payroll and avoid common errors?

Most payroll problems are process problems rather than maths problems. The errors that show up most often are also the easiest to design out:

• Missed or unapproved timesheet edits, which remain the single most common source of payroll error.
• Treating a non-exempt employee as exempt, or an employee as a contractor.
• Applying deductions out of order, which changes every withholding underneath them.
• Missing a deposit deadline, which carries a fixed percentage penalty regardless of how small the shortfall is.
• Stale employee data: old addresses, closed bank accounts, outdated withholding elections.

A short pre-run checklist and a quarterly self-audit catch nearly all of these before an employee or an agency does.

The cost is not theoretical. An Ernst & Young survey of US employers found that one in five payrolls contains an error, that each error costs an average of $291 to put right, and that a company with 1,000 employees spends roughly 29 workweeks a year fixing them. None of that shows up as a line item, which is exactly why it goes unmanaged.

"The Payroll Book will be a valuable resource for the small business owner as well as for the entrepreneur planning a new venture. Thorough, well-organized, and thoughtfully written, this practical guide is an essential tool for managing the payroll process." Marilyn K. Wiley, Dean of the College of Business, University of North Texas, on The Payroll Book by Charles Read

Year end is its own project: reconcile the four quarterly returns against your annual totals, confirm names and addresses, then issue W-2s and 1099-NECs by January 31 and file the annual FUTA return. Every ordinary run also ends in a document the employee reads closely, so it pays to be deliberate about what belongs on it.

(See: pay stub)

Why does payroll matter for business success?

Payroll is the one process where a small mistake reaches every employee personally and every regulator formally. Pay someone late or short and you have damaged trust that took months to build. Miss a deposit and you have created a liability that grows on a fixed schedule whether you notice it or not.

That is why the choice between in-house, software and outsourcing is worth revisiting each time you add a state, a country or a headcount bracket. The method that suited five people rarely suits fifty. Understand the calculations, keep the calendar visible, and the rest becomes a routine you can hand over with confidence.

Why choose Wisemonk to run your payroll?

Wisemonk is an Employer of Record that helps global companies hire, pay and manage talent compliantly, without setting up a local entity first. We work with 300+ global clients, employ 2,000+ people, process over $20M in annual payroll, hold a 4.8/5 rating on G2, and start from $99 per employee per month.

Here is what comes off your plate:

• Payroll processing and statutory compliance: every cycle runs accurately and on time, with the filings and contributions handled for you.
• Employer of Record hiring: we become the legal employer so you can bring people on without your own entity.
• Benefits administration: we set up and manage competitive employee benefits for your team.
• Equipment procurement: we source, ship and manage laptops and devices wherever your people are.
• Contractor management: we onboard, contract and pay contractors through one platform.

Those five together are the difference between owning payroll as a monthly risk and treating it as a service you receive.

What do clients say about working with Wisemonk?

Companies across the US, UK and Europe use us to build teams compliantly and quickly. One short example of how that plays out in practice.

Cobu, engineering team build. Cobu needed engineers in a market where it had no entity and no local HR presence, which meant hiring, payroll and compliance all had to be solved at once. We ran the search against their criteria, handled the interviews and onboarding, and took on employment, payroll and compliance as the legal employer. The engineers hired through that process became part of their core team, and their pricing was clear from the first conversation rather than the third invoice.

"I'm very happy that I discovered Wisemonk. They have been a pure pleasure to work with, and their attention to detail is impressive. They helped us understand their pricing model, find top-qualified individuals, interview them, and then onboard them. I gave them criteria for the type of people we sought, and they delivered. The individuals they were able to find have been some of the best engineers I have ever worked with. I recommend Wisemonk to anyone who is in need of staffing assistance." Dan Sampson, Head of Engineering at Cobu