You will get a P45 from your employer when you stop working for them.
If you are an employer, find out how to get an employee’s P45 (external link).
Your P45 shows how much tax you have paid on your salary so far in the tax year (6 April to 5 April).
A P45 has 4 parts (Part 1, Part 1A, Part 2 and Part 3).
Your employer sends details for Part 1 to HM Revenue and Customs (HMRC) and gives you the other parts.
You give Part 2 and 3 to your new employer (or to Jobcentre Plus if you’re not working).
Keep Part 1A for your own records.
By law your employer must give you a P45 - ask them for one.
You can check how much tax you paid last year (external link) if you think you might have paid too much.
You do not have a P45
You will not have a P45 if you are starting your first job or you are taking on a second job. Your employer will need to work out how much tax you should be paying on your salary.
They may use a ‘Starter Checklist’ to collect the information, or may collect it another way. The Starter Checklist has questions about any other jobs, benefits or student loans you have. It helps your employer work out your correct tax code before your first payday.