Self-service payroll means in-house payroll. You might use software to run the numbers and simplify direct deposit, but in the end, you’re responsible for payroll tax compliance and making sure employees get paid the right amount. In contrast, if you run full-service payroll, you outsource at least some parts of your payroll process to another company. Full-service payroll usually costs more than self-service payroll, but it saves you time, which could translate to saved money. Most importantly, a full-service payroll company takes on the responsibility for withdrawing the right amount of taxes. If there’s an issue with federal or local taxes, it’s the payroll company’s problem, not yours.