You can, and many small businesses do. Missouri doesn’t require you to use a payroll service or accountant. The question is whether doing it yourself is actually worth the time and risk.

Running payroll involves more than writing checks. You need to calculate federal income tax withholding based on each employee’s W-4. You need to calculate and withhold Social Security and Medicare taxes. You need to pay the employer portion of those taxes. Missouri requires state income tax withholding. If your employees work in Kansas City or St. Louis, you also withhold local earnings taxes.

Those calculations happen every pay period. Then you have to deposit the taxes on schedule. Federal deposits are either monthly or semi-weekly depending on your total tax liability. Miss a deposit deadline and penalties start immediately. Missouri has its own deposit schedule for state withholding.

Quarterly, you file Form 941 with the IRS and wage reports with Missouri. Annually, you prepare W-2s for employees and file W-3s with the Social Security Administration. Each form has a deadline. Each missed deadline has a penalty.

Payroll software makes the math easier. QuickBooks Payroll, Gusto, and similar tools calculate withholdings, generate pay stubs, and remind you of deadlines. Some even file the forms and make the deposits for you. The software costs money, but it eliminates most calculation errors.

Where businesses get into trouble isn’t usually the math. It’s the compliance. Depositing taxes late. Filing quarterly reports after the deadline. Misclassifying employees as contractors. Forgetting to issue 1099s to subcontractors. Each mistake carries penalties, and they add up fast. A Mid-Missouri bookkeeper can help you understand the requirements and set up systems that keep you compliant from the start.

The time cost matters too. Even with software, someone has to enter hours, verify calculations, approve payments, reconcile accounts, and stay current on changing tax rates and rules. For a business owner, that’s time not spent on work that generates revenue.

DIY payroll makes sense when you have one or two employees, simple pay structures, and the discipline to hit every deadline without fail. Once you add multiple employees, varying pay rates, benefits, or just inconsistent schedules, the complexity grows faster than most owners expect.

For businesses past the earliest stages, outsourcing payroll processing typically costs less than the penalties from one missed deadline. It also frees up hours every month that most business owners would rather spend elsewhere.