What Is a P45? Your Guide When You Leave a Job

When you leave a job in the UK, your employer gives you a form called a P45. It is one of the most important tax documents you will handle, because it makes sure you pay the right tax when you start your next job, and getting it wrong is a common reason people overpay. This guide explains what a P45 is, what is on it, and what to do with it.

What is a P45?

A P45 is the form you get from an employer when you stop working for them. It is a record of how much you have earned and how much tax you have paid in the current tax year up to your leaving date. Its official name is “Details of employee leaving work”.

Your employer must give it to you when you leave, and they also send the information to HMRC.

What is on a P45?

A P45 shows:

• Your total pay and the tax deducted so far in the current tax year.
• Your tax code at the time you left.
• Your National Insurance number and the dates of your employment.
• Your employer’s PAYE reference.

It comes in parts. Part 1 goes to HMRC, and you receive Part 1A for your records, plus Parts 2 and 3 to give to your new employer.

Why a P45 matters

When you start a new job, you give Parts 2 and 3 of your P45 to your new employer. This tells them your earnings and tax so far, so they apply the correct tax code and you pay the right amount. Without it, you can be put on an emergency tax code and overpay until HMRC catches up.

What if I do not have a P45?

If you do not have a P45, for example because you are starting your first job, returning to work, or your old employer was slow to provide it, your new employer will use a starter checklist instead. This often means an emergency tax code to begin with, which can lead to overpaying, so it is worth checking your code once your pay settles.

How a P45 links to overpaid tax

If you changed jobs and your P45 details were not used correctly, or you were on an emergency code for a while, you may have paid too much tax. That overpayment can usually be reclaimed, including for past years within the four year window.

Frequently asked questions

How long should I keep my P45?

Keep Part 1A for your records for several years, as it is useful evidence of your pay and tax.

I lost my P45. Can I get a replacement?

Employers cannot reissue a P45, but your new employer can use a starter checklist, and your pay and tax details are available in your HMRC Personal Tax Account.

Does a P45 mean I am owed a refund?

Not by itself, but leaving a job mid-year, or being on an emergency code afterwards, is a common cause of overpaying, which can be reclaimed.

What is the difference between a P45 and a P60?

A P45 is given when you leave a job. A P60 is an end-of-year summary given by your current employer if you are still working for them at 5 April.

Changed jobs recently? You may have overpaid

Job changes and emergency tax codes are one of the most common reasons people overpay tax, often without realising.

Start your claim with TaxPro and we will check whether you are owed a refund, on a no win, no fee basis.