Payroll for Small Business: What Every Employer Needs to Know

Miss one payroll tax deposit deadline and the penalty starts at 2% of the unpaid amount — and climbs to 15% the longer it goes unpaid. Misclassify one employee as a contractor and you could owe back payroll taxes, interest, and penalties going back years. For a business with two or twenty employees, payroll isn’t just “paying people.” It’s one of the most heavily regulated, deadline-driven tasks a small business owner handles, and the IRS, state agencies, and the Department of Labor all have a stake in you getting it right.

The good news: payroll follows a predictable structure once you understand the pieces. This guide walks through what payroll actually involves, the taxes you’re on the hook for, how to set it up correctly, and the mistakes that trip up most first-time employers.

What Payroll Actually Involves for a Small Business

Payroll is more than cutting a check. Each pay period, an employer needs to:

• Calculate gross wages, including overtime under the Fair Labor Standards Act (time-and-a-half for hours worked over 40 in a week for non-exempt employees)
• Withhold federal income tax, Social Security, and Medicare (FICA) based on each employee’s Form W-4
• Withhold applicable state and local income taxes
• Match the employee’s FICA contribution as the employer
• Calculate and remit federal (FUTA) and state (SUTA) unemployment taxes
• Deposit withheld taxes with the IRS and state agencies on the correct schedule
• File quarterly and annual payroll tax returns (Form 941, Form 940, and state equivalents)
• Issue W-2s to employees and 1099-NECs to contractors by January 31 each year

Each of those steps has its own deadline, form, and penalty for getting it wrong. That’s why accurate bookkeeping and payroll records need to work together — payroll errors almost always show up as bookkeeping errors too.

Employee vs. Independent Contractor: Get This Right First

Before you run your first payroll, you need to know who actually belongs on it. The IRS uses a behavioral, financial, and relationship-based test to determine worker classification — essentially, how much control you exercise over how, when, and where the work gets done. A worker you direct closely, provide equipment to, and expect to work set hours is almost always an employee, not a contractor, regardless of what the agreement says.

Misclassification is one of the most common (and expensive) payroll mistakes small businesses make. If the IRS reclassifies a contractor as an employee retroactively, you can owe back FICA taxes, unemployment taxes, and penalties for every pay period the person worked. If you’re unsure, the IRS allows you to file Form SS-8 for a determination, though many businesses find it faster to get a professional opinion first.

Setting Up Payroll: Step-by-Step

1. Get an EIN. You need a federal Employer Identification Number from the IRS before you can run payroll, even if you already have a business bank account.
2. Register for state and local tax accounts. Most states require separate registration for income tax withholding and unemployment insurance.
3. Collect Form W-4 and Form I-9 from every new hire. The I-9 confirms work eligibility and must be completed within three business days of the start date; keep it on file, not submitted anywhere.
4. Report new hires to your state. Federal law requires new hire reporting within 20 days of the hire date (some states require faster reporting).
5. Set up workers’ compensation insurance. Nearly every state requires it once you have employees, even part-time ones.
6. Choose a pay schedule. Weekly, biweekly, semimonthly, or monthly — many states set minimum pay frequency requirements, so check your state’s rules before deciding.
7. Pick a payroll system. Software like QuickBooks Payroll or Gusto, or a payroll service, will calculate withholdings and file forms for you.

If you’re already using QuickBooks or Xero for your books, connecting payroll to the same system keeps your general ledger accurate without double entry.

Payroll Taxes You’re Responsible For

As an employer, you’re paying two kinds of payroll tax: what you withhold from employee wages, and what you owe on top of wages out of your own pocket.

• FICA (Social Security & Medicare): 7.65% withheld from the employee’s pay, matched with another 7.65% from the employer — 15.3% total. An additional 0.9% Medicare surtax applies to employee wages above $200,000, with no employer match.
• Federal income tax withholding: Based on the employee’s W-4 elections and the IRS withholding tables; this money belongs to the employee and simply passes through you.
• FUTA (federal unemployment): 6.0% on the first $7,000 of each employee’s wages, though most employers who pay state unemployment on time receive a credit that lowers the effective rate to 0.6%.
• SUTA (state unemployment): Rate and wage base vary by state and by your claims history — new employers typically start at a standard rate until they build a track record.

Federal payroll tax deposits are due either monthly or semiweekly, depending on your total tax liability during a prior lookback period, and the IRS notifies you of your schedule. Deposits are made electronically through EFTPS. Missing a deposit deadline triggers a penalty that starts at 2% for deposits 1–5 days late and rises to 15% for amounts still unpaid more than 10 days after an IRS notice, according to IRS guidance on Form 941 deposit penalties. Quarterly, you’ll file Form 941 to reconcile what you withheld and deposited; annually, Form 940 reports your FUTA liability.

How Often Should You Run Payroll?

Biweekly (every two weeks, 26 pay periods a year) is the most common schedule among small businesses because it balances administrative workload with employee cash-flow needs. Semimonthly (twice a month, 24 pay periods) simplifies benefits and salary math since paychecks land on the same two dates each month. Weekly payroll is more common in industries with hourly, variable-hour staff, like restaurants and construction, where employees prefer more frequent pay. Whatever you choose, check your state’s minimum pay frequency law first — several states require at least semimonthly pay for non-exempt employees regardless of employer preference.

Common Payroll Mistakes That Cost Small Businesses Money

• Missing tax deposit deadlines. Even a few days late triggers IRS penalties, and interest accrues on top.
• Misclassifying workers as contractors. This is one of the top triggers for a Department of Labor or IRS audit.
• Forgetting overtime for non-exempt salaried employees. Salary alone doesn’t exempt someone from overtime — the role has to meet specific duties tests under the FLSA.
• Not keeping up with state minimum wage changes. Many states and cities set minimum wages above the federal $7.25/hour floor, and those rates often change every January.
• Treating payroll and bookkeeping as separate systems. When payroll isn’t reconciled against your books monthly, small errors compound into a mess by year-end.
• Losing track of new hire paperwork. Missing I-9s or late new-hire state reporting can each carry separate fines.

DIY Payroll vs. Payroll Software vs. Outsourcing

Running payroll manually — calculating withholdings by hand and mailing deposits — is technically possible but risky; a single miscalculation on FICA or a missed deposit date creates real penalties. Payroll software (QuickBooks Payroll, Gusto, ADP) automates the math and often files your 941s and W-2s for you, which removes most of the calculation risk but still leaves you responsible for reviewing accuracy and staying current on rate changes. Outsourcing payroll to a bookkeeping or accounting service adds a layer of review: someone with accounting expertise checks classifications, catches discrepancies before they become penalties, and keeps payroll reconciled with your books every month. For business owners who’d rather spend their time running the business than tracking tax deposit calendars, that oversight is usually worth the cost of the mistakes it prevents.

If you’re weighing the cost of outsourcing against doing it in-house, Ask For CPA’s payroll services handle calculations, deposits, and filings alongside your monthly bookkeeping, and our pricing page breaks down what’s included at each service tier.

Frequently Asked Questions

Do I need payroll software if I only have one or two employees?

You’re not legally required to use software, but the risk of a manual calculation error doesn’t shrink just because you have fewer employees — the IRS penalty structure is the same. Most payroll software plans for one to five employees cost less per month than a single late-deposit penalty, which makes automation worthwhile even at small scale.

What’s the penalty for classifying an employee as a contractor by mistake?

If the IRS determines a worker was misclassified, you can owe the employer and employee share of FICA taxes going back to when the work began, plus federal unemployment tax, plus penalties and interest. Relief programs exist (such as the IRS Voluntary Classification Settlement Program) for businesses that come forward proactively, which is generally far less costly than being caught in an audit.

How do I know if I’m a monthly or semiweekly depositor?

The IRS assigns your deposit schedule each year based on your total employment tax liability during a 12-month lookback period ending the prior June 30. Businesses with $50,000 or less in liability during that period are monthly depositors; above that, you’re a semiweekly depositor. The IRS notifies new employers directly, and payroll software will also flag which schedule applies to you.

Can I run payroll myself using just a spreadsheet?

Technically yes, but it’s not recommended beyond a single owner-employee setup. Spreadsheets don’t automatically update tax rates, don’t file your 941s or W-2s, and put the full burden of catching errors on you. The time saved rarely offsets the penalty risk once you have even one or two employees on the books.

Payroll tax rules change year to year and vary by state, so treat the figures above as general guidance rather than advice for your specific situation. A licensed CPA or payroll professional can confirm the requirements that apply to your business before you run your first payroll.

Getting payroll right the first time is far cheaper than fixing it after an IRS notice. If you’d rather hand off deposits, filings, and reconciliation to someone who does this daily, get in touch with Ask For CPA and we’ll walk you through how our bookkeeping and payroll services can take this off your plate.