Payroll processing is six steps, not one: calculate gross pay, withhold, calculate employer taxes, pay employees, remit taxes, and file returns. The last two carry the legal risk.
Budget payroll as wages plus roughly 8 to 10%. The employer share of Social Security and Medicare alone is 7.65%.
Three separate clocks run at once: deposits (monthly or semiweekly), quarterly Form 941 filings, and annual W-2 and 1099-NEC reporting due January 31.
Depositing taxes and filing returns are different obligations. Doing one does not satisfy the other.
Hiring in a new state usually means registering with that state before the employee's first paycheck.
Misclassifying an employee as a contractor is the most expensive early payroll mistake, and the test is control, not the contract.
Outsourcing payroll moves the work but not the liability. Ask any provider which filings it submits and which remain yours.
Most payroll guides are written for HR departments at companies that already have one. This one is written for the person who just hired their first employee and now has to understand a system nobody explained to them.
Payroll processing is the mechanical part of paying people: calculating what each person earned, withholding the right amounts, sending the money, paying the government its share, filing the paperwork that proves you did it, and keeping records long enough to survive an audit. Software can automate almost all of it. None of it stops being your legal responsibility.
Here's how the system works, in the order it actually happens.
What payroll processing actually means
Payroll processing is often confused with paying people. Paying people is one step out of six.
A complete payroll run does all of this:
Calculates gross pay for every worker, including overtime, bonuses, and commissions
Withholds income taxes and any voluntary deductions from each paycheck
Calculates employer taxes, which come out of your money, not the employee's
Distributes net pay by direct deposit, check, or pay card
Remits the withheld and employer taxes to federal, state, and sometimes local agencies
Files returns that report what you paid and withheld
Miss the first four and someone doesn't get paid. Miss the last two and you accrue penalties and interest, usually without anyone telling you until much later.
A few terms you'll meet immediately:
Gross pay is what someone earned before anything is taken out. Net pay is what actually lands in their account. Withholding is money you take from an employee's pay and hold in trust for a tax agency. Remittance is sending that money on. A payroll register is the internal record of one pay run, listing every worker, their gross pay, each deduction, and their net pay. A pay stub is the employee-facing version of that same information. An EIN is the Employer Identification Number the IRS issues you, and you cannot run payroll without one.
The payroll cycle: periods, cutoffs, and pay dates
Three dates govern every pay run, and confusing them is the most common early mistake.
The pay period is the stretch of time being paid for, such as the first through the fifteenth. The cutoff is when timesheets and changes must be final. The pay date is when money reaches employees. The gap between cutoff and pay date exists because calculation, funding, and bank transfer all take time.
Your pay frequency determines how often this repeats:
Frequency | Pay runs per year | Notes |
Weekly | 52 | Common for hourly teams; the most administrative work |
Biweekly | 26 | Every other week, so two months a year have three pay dates |
Semi-monthly | 24 | Fixed dates, often the 15th and last day |
Monthly | 12 | Least work, hardest on employees' cash flow |
Some states set a minimum pay frequency, and some restrict which frequencies you can use for hourly workers. Check your state's rule before you pick, because changing it later means notifying employees and sometimes waiting a full cycle.
One practical warning about biweekly: those two three-paycheck months will break your cash forecast if you budgeted payroll as a flat monthly number.
What gets calculated in a pay run
Every paycheck is the same arithmetic, run per person.
Start with gross pay. For salaried people, it's the annual salary divided by the number of pay periods. For hourly people, it's hours times rate, plus overtime. Under federal law, non-exempt employees earn at least 1.5 times their regular rate for hours over 40 in a workweek. Several states add daily overtime rules on top.
Subtract pre-tax deductions. Health insurance premiums and traditional 401(k) contributions usually come out before taxes, which lowers taxable wages.
Withhold employee taxes. This is federal income tax based on the employee's Form W-4, plus Social Security at 6.2% and Medicare at 1.45%, plus state and sometimes local income tax. An additional Medicare tax of 0.9% applies to employee wages above $200,000, and the employer does not match that piece.
Subtract post-tax deductions. Roth 401(k) contributions, wage garnishments, and some benefits come out after tax.
What's left is net pay.
Then, separately, you calculate what you owe as the employer. This is not deducted from anyone's paycheck:
Social Security, 6.2%, matching the employee, up to an annual wage base the Social Security Administration adjusts each year
Medicare, 1.45%, matching the employee, with no wage cap
FUTA, the federal unemployment tax, 6.0% on the first $7,000 of each employee's wages, though a credit of up to 5.4% for state unemployment taxes brings most employers to 0.6%
SUTA, state unemployment tax, at a rate your state assigns you based on your industry and claims history
Together, the employer share of Social Security and Medicare is 7.65% of wages. Budget for payroll as roughly wages plus 8 to 10%, not wages alone.
Federal and state tax obligations
This is where startups get into trouble, because the obligations are on three separate clocks.
Depositing. Withheld taxes plus your matching share get deposited electronically through the Electronic Federal Tax Payment System, or EFTPS. Your schedule depends on your history: if your reported employment taxes in the lookback period, the four quarters ending June 30 of the prior year, were $50,000 or less, you deposit monthly, by the 15th of the following month. Above $50,000, you deposit semiweekly. New employers default to monthly for their first calendar year. Separately, if accumulated taxes hit $100,000 on any day, you must deposit by the next banking day regardless of schedule.
Filing. Depositing money is not the same as reporting it. You file Form 941 quarterly, due April 30, July 31, October 31, and January 31. You file Form 940 annually for FUTA, due January 31. States have their own returns on their own schedules.
Year-end reporting. You give employees a Form W-2 and file copies with the Social Security Administration by January 31. Contractors who earned $600 or more get a Form 1099-NEC, also due January 31.
Multi-state. Hiring someone in a new state generally means registering with that state's tax and unemployment agencies before their first paycheck. Remote hiring makes this routine, and it's the obligation founders most often discover late.
The IRS publishes the authoritative detail in Publication 15, the Employer's Tax Guide, and withholding mechanics in Publication 15-T.
Direct deposit and payment timing
Most payroll moves by ACH, the bank network that handles direct deposit. ACH is not instant. A standard ACH credit settles in one to two business days, which is why your provider debits your account before employees see the money.
Two consequences worth planning around. First, your funding account needs the full amount, wages plus employer taxes, available at the debit date, not the pay date. Second, bank holidays shift everything. A Friday pay date with a Thursday holiday usually means submitting a day earlier.
If you miss the funding window, payroll can fail for everyone in the run, not just the person you were short on.
Payroll records you're required to keep
Two different agencies impose two different retention rules, so keep records to the longer one.
The IRS expects employment tax records kept at least four years after the tax is due or paid. The Fair Labor Standards Act requires payroll records for three years, and records used to compute wages, like time cards, for two years.
In practice, keep these for every employee: name, address, and Social Security number; Form W-4; Form I-9 verifying work eligibility; hours worked; wages paid and the basis for them; all deductions; and copies of filed returns. Keep signed Form W-9s for contractors.
Store them somewhere that survives switching providers. Records held only inside a payroll platform you later leave are records you may not be able to produce.
Common mistakes first-time founders make
Misclassifying employees as contractors. This is the expensive one. Calling someone a 1099 contractor when you control how, when, and where they work invites back taxes, penalties, and interest. The test is about control and independence, not what the contract says or what the worker prefers.
Treating withheld taxes as available cash. Withheld money isn't yours. The IRS treats unpaid trust-fund taxes seriously, and responsible individuals can be held personally liable.
Missing the state step when hiring remotely. A new state usually means new registrations, new rates, and new returns.
Forgetting that stipends and gifts are usually wages. Cash stipends, most gift cards, and many perks are taxable compensation and belong in payroll, not in an expense report.
Paying founders informally. If you're a W-2 employee of your own company, you run yourself through payroll like anyone else. Owner draws from an S corporation with no reasonable salary are a well-known audit trigger.
Assuming the provider carries the liability. Outsourcing payroll moves the work. Penalties for late or incorrect filings still land on your business.
What to look for when choosing a payroll solution
Evaluate on the obligations above rather than on feature lists.
Which filings does it submit for you, and which stay yours? Get this in writing. It's the line that determines where liability sits.
Does it register you in new states as you hire? Some do it, some hand you forms, some ignore it.
How does it handle contractors alongside employees? Most startups run both.
What does it cost at your real headcount? Per-employee pricing at ten people looks nothing like fifty.
How does payroll data reach your accounting system? Automatic journal entries or a manual export changes your monthly close.
Can you export your records if you leave? Ask before you sign.
What happens when something's wrong? Ask how corrections and amended returns work, and who pays the penalty if the error was theirs.
Payroll is one of the few systems where the boring questions matter more than the impressive ones. A platform that files accurately and tells you when a state registration is missing is worth more than one with a better dashboard.
Frequently asked questions
What is payroll processing?
Payroll processing is the full cycle of paying employees: calculating gross pay, withholding taxes and deductions, calculating employer taxes, distributing net pay, remitting taxes to government agencies, and filing the required returns. Paying people is one step; the tax remittance and filing steps are where legal liability sits.
How long does payroll processing take?
With payroll software and clean time data, a small startup pay run takes about 15 to 30 minutes of active work. The bank transfer adds one to two business days, which is why providers debit your account before the pay date. First-time setup takes considerably longer because of registrations and employee paperwork.
What taxes does an employer pay on payroll?
Employers pay 6.2% for Social Security up to an annual wage base and 1.45% for Medicare with no cap, which is 7.65% combined. Employers also pay FUTA at 6.0% on the first $7,000 of each employee's wages, usually reduced to 0.6% by a credit of up to 5.4% for state unemployment taxes, plus state unemployment tax at a state-assigned rate.
How often do I have to deposit payroll taxes?
It depends on your history. If your reported employment taxes during the lookback period, the four quarters ending June 30 of the prior year, were $50,000 or less, you deposit monthly by the 15th of the following month. Above that, you deposit semiweekly. New employers are monthly depositors for their first calendar year, and any employer that accumulates $100,000 in taxes must deposit by the next banking day.
What's the difference between gross pay and net pay?
Gross pay is total earnings before anything is withheld. Net pay is what reaches the employee's bank account after income tax withholding, Social Security and Medicare, and any pre-tax and post-tax deductions.
How long do I need to keep payroll records?
Keep employment tax records at least four years per the IRS, and payroll records three years under the Fair Labor Standards Act, with wage-computation records like time cards for two years. Keeping everything for four years satisfies all three, and you should store records somewhere you'll still control if you change providers.
Do I need an EIN to run payroll?
Yes. You need an Employer Identification Number from the IRS before you can withhold and remit payroll taxes. Most states also require a separate state tax and unemployment insurance registration before an employee's first paycheck.