Why Payroll Tax Withholding Matters
Payroll tax withholding is the mechanism by which employers collect taxes from employees on behalf of the government throughout the year. Rather than employees paying a lump sum at tax time, taxes are deducted from each paycheck incrementally. As an employer, you are legally responsible for calculating, withholding, and remitting these amounts accurately and on time.
The Main Types of Payroll Tax Withholding
1. Federal Income Tax
Federal income tax withholding is based on the employee's Form W-4 (Employee's Withholding Certificate). The amount withheld depends on the employee's filing status, any claimed adjustments, and their wage level. The IRS provides two methods for calculating this: the Wage Bracket Method (using tables) and the Percentage Method.
Employees should update their W-4 whenever their personal or financial situation changes — marriage, divorce, a second job, or having a child can all affect the correct withholding amount.
2. FICA Taxes: Social Security & Medicare
FICA (Federal Insurance Contributions Act) taxes fund Social Security and Medicare programs. Both the employee and employer each pay half:
- Social Security: 6.2% withheld from the employee + 6.2% paid by the employer (applies up to the annual wage base limit set by the IRS each year)
- Medicare: 1.45% withheld from the employee + 1.45% paid by the employer (no wage cap)
- Additional Medicare Tax: An extra 0.9% withheld from employees earning above $200,000 in a calendar year (no employer match on this portion)
3. State Income Tax
Most states levy their own income tax that employers must withhold from employee paychecks. Rates and rules vary widely. A handful of states — including Texas, Florida, Nevada, and Washington — have no state income tax. Always verify the current requirements for every state where your employees work, not just where your business is headquartered.
4. Local Taxes
Some cities and counties impose their own payroll or income taxes (common in states like Ohio, Pennsylvania, and New York). These are easy to overlook but just as mandatory as state and federal obligations.
Employer Tax Deposits: When and How
The IRS requires employers to deposit withheld federal taxes plus the employer share of FICA on a set schedule — either monthly or semi-weekly, depending on the total taxes reported in the IRS's "lookback period." New employers typically start as monthly depositors.
Deposits are made electronically through the Electronic Federal Tax Payment System (EFTPS). Late or missed deposits trigger penalties that escalate the longer the deposit remains outstanding.
Key Filing Deadlines to Know
- Form 941 (Employer's Quarterly Federal Tax Return): Due by the last day of the month following each quarter end.
- Form 940 (Annual FUTA Tax Return): Due January 31 for the prior year.
- W-2s to Employees: Must be distributed by January 31 each year.
- W-2s to SSA: Also due January 31.
Common Withholding Mistakes to Avoid
- Not collecting an updated W-4 when an employee's circumstances change.
- Using outdated tax tables instead of the current-year IRS Publication 15-T.
- Misclassifying workers as independent contractors to avoid withholding obligations.
- Forgetting to account for supplemental wage withholding rules (bonuses, commissions).
- Missing state or local tax registrations when hiring remote employees in new states.
Keeping up with withholding requirements is one of the most critical parts of running payroll. When in doubt, consult a payroll professional or CPA, especially if you're operating across multiple states.