The monthly subscription cost is where most business owners start and stop their comparison. QBO Payroll runs $45 to $125 per month depending on the plan. Outsourced full-service payroll typically runs $50 to $200 per month for a small business. Looking at those numbers alone, the difference seems small. But the subscription fee is only one piece of the real cost.

Running payroll in-house takes time. Depending on how many employees you have, the pay structure, and whether you have overtime or varying hours, expect to spend 2 to 8 hours per pay period processing payroll. That includes reviewing timesheets, entering hours, verifying calculations, and making sure tax withholdings are correct. If you’re running biweekly payroll on the higher end of that range, you’re spending 16 or more hours a month on payroll alone. What’s your time worth? Even at a modest $50 per hour, that’s $800 a month in time you could spend on revenue-generating work.

Then there’s the cost most people don’t think about until it hits them. IRS payroll tax penalties start at 2% of the unpaid amount if you’re just a few days late. They escalate to 5%, then 10%, and top out at 15% if taxes remain unpaid after the IRS sends a notice. Miss a quarterly filing or deposit a day late and you’re facing penalties that can easily exceed what you would have paid someone else to handle everything for the entire year. Arizona has its own penalties on top of federal ones for late or incorrect state filings.

Full-service payroll means someone else handles the tax deposits, quarterly filings, and year-end W-2 preparation. They stay current on tax law changes so you don’t have to. When Arizona updates a withholding rate or the IRS changes a form, that’s their problem to solve, not yours. With in-house payroll, every compliance change is something you need to catch and implement correctly.

The error risk goes beyond penalties. Incorrect withholding means employees get surprise tax bills and blame you. Misclassifying a worker as a contractor when they should be an employee triggers back taxes and penalties from both the IRS and Arizona. Full-service payroll providers build compliance checks into their process so these mistakes get caught before they become expensive.

There is a middle ground that works for some businesses. If you want to keep payroll in-house but need it set up correctly from the start, getting professional help with configuration and training can reduce your ongoing risk significantly. The key is making sure your tax accounts, withholding settings, and filing schedules are right before you ever run your first payroll.

For most small businesses in Phoenix, the math favors outsourcing. The monthly cost difference between doing it yourself and having someone else handle it is usually less than $100. That buys you back hours of time every pay period and eliminates the risk of a penalty that could run into thousands. As Phoenix bookkeepers who work with businesses across the Valley, we’ve seen owners spend more cleaning up payroll mistakes than they would have spent outsourcing for years. The cheapest option isn’t always the one with the lowest monthly fee.