A payroll number is a unique identifier that businesses use to identify employees for payroll purposes. It is a series of numbers and/or letters assigned to each individual employee to ensure they are paid correctly and to track employee information and personal data. The payroll number allows a business to track its employees through the use of this unique identifier rather than by their name or other personal information which can lead to payroll errors. The payroll number is usually three to eight digits long, depending on the number of employees in the department, and is usually located at the upper right or left-hand corner of the payslip. The payroll number is distinct from other reference numbers such as a UK Employer Reference Number (ERN Number) which is also referred to as a PAYE reference number. The payroll number is important for accurate and secure payroll records, and it is usually issued by the human resource department of an organization upon hiring of the employee. The payroll number is used in payroll management software programs as a basis for the tracking and paying of the salary to the employee.