RTI - since April 2013 changes have been made to the system of staff and salaries and consisting of monthly informing the HMRC about earnings of each employee and the date of employee acceptance or the date of employee leaves the company.
Payroll - We prepare payroll for employees, that means the calculations of every payments, overtimes, commissions, official wages, maternity payments, statutory sick pays and holidays payments.
P45 - It's provided to employees that leaves the company. It's a calculation of earnings and paid tax.
P60 - If an employee stay in the company, when the tax year is finished (untill 5th of April) employer is obligated to provide the annual calculation of earnings and paid tax.