You will need to complete the following forms or maintain the equivalent digital records:
P11 Deductions working sheet
This form (or a computer generated equivalent) must be maintained for each employee. It details their pay and deductions for each week or month of the tax year.
P60 End of year summary
This form has to be completed for and given to all employees employed in a tax year.
P45 Details of employee leaving
This form needs to be given to any employee who leaves and details the earnings and tax paid so far in the tax year. New employees should let you have the form P45 from their previous employer.
When a new employee starts, you will need to advise HMRC so that you can pay them under RTI. Some of the necessary information may be obtained from the P45 if the employee has one from a previous job.