The P45 is a certificate, which contains earnings and tax payments over the financial tax year up until when employee leaves job, and it is issued to employee by the employer. P45 shows how much tax you've paid on your salary so far in the tax year. 

P45 is printed using a laser printer. This new format P45 is applicable for leaving date after 1/10/2008. The main differences from the old format P45 are the new required fields: Date of birth, Gender

It is the summary of: Employer Name & Address, Employee Name & Address, Date of birth, Gender, National Insurance number, PAYE Tax code, Staff/Employee number (if any), Employer Tax office reference, Date of leaving, Total Pay to date & Total Tax to date

This P45 comprises of 4 parts, each part on a separate A4 sheet: Employer submits Part 1 to their tax office and gives employee the other 3 parts. Part 1A is for employees records and Parts 2 & 3 are for the new Employer or Jobcentre, if claiming benefits. We supply P45 form containing Parts 1A, 2, 3