What payroll requirements come with running an S-corp?

Once you elect S-corp treatment and take a reasonable salary, you become an employer with real obligations — even as a one-person business. You must run formal payroll: withhold federal income tax, Social Security, and Medicare from your paycheck, pay the employer share, and deposit those taxes on the IRS schedule. You'll file quarterly Form 941 (or annual 944), issue yourself a W-2 each January, file federal and state unemployment returns, and handle any state withholding. Miss deposits and the penalties are steep. Practically, almost no S-corp owner does this by hand — a payroll service automates the withholding, deposits, and filings for a modest monthly fee, and that cost is part of what you weigh against the S-corp's tax savings. If payroll complexity feels heavy for your profit level, the S-corp may not yet be worth it.