The Missouri Common Paymaster Law is a law that allows two or more employers to combine their payrolls and establish a single paymaster to process payroll for all employers. This law helps employers save money and time by allowing them to share payroll processing and administrative costs. There are two types of Missouri Common Paymaster Law: voluntary and mandatory. The voluntary law allows employers to opt into the common paymaster program if they choose, while the mandatory law requires employers to use a common paymaster if they employ 25 or more workers. Under both laws, employers must enter into a written agreement with their common paymaster that outlines the responsibilities of each party. Additionally, the common paymaster must register with the state of Missouri and follow all applicable labor laws.