A P45 is one of those documents everyone has heard of but few fully understand. You get one each time you leave a job, and handing it to your next employer helps make sure you pay the right tax. This guide explains what a P45 is, what it shows, and what to do with it in 2026/27.
What is a P45?
A P45 is a document your employer gives you when you stop working for them. It records how much you have earned and how much tax you have paid in the current tax year up to your leaving date, along with your tax code. Its formal name is the details of employee leaving work form, but everyone calls it a P45.
What information does it show?
Your P45 shows your leaving date, your total pay and the tax deducted so far in the tax year, your tax code at leaving, and your National Insurance number and an employer reference. It comes in several parts. You keep one part and give the others to your new employer or, if you are claiming benefits, to the relevant office.
Why your new employer needs it
When you start a new job, giving your new employer your P45 lets them set you up on the correct tax code straight away, using the figures from your previous job. Without it, they have to use an emergency code or a starter checklist, which can mean you pay too much tax for a while until HMRC corrects things.
What if you do not have a P45?
You will not always have a P45, for example if this is your first job, you had a gap, or your old employer was slow to provide one. In that case your new employer will ask you to complete a starter checklist instead, which gathers the same basic information so HMRC can work out your code. You will not be stuck without one, it just may take a little longer to get onto the right code.
Lost your P45?
Employers cannot issue a duplicate P45, so if you lose it, you cannot simply ask for another. Instead, your new employer uses the starter checklist, and your Personal Tax Account shows your pay and tax history. So a lost P45 is not a disaster, although it is worth keeping the one you are given.
P45 versus P60
The two are easy to mix up. A P45 is given when you leave a job and covers your pay and tax up to that point. A P60 is given at the end of each tax year while you are still employed and summarises the whole year. You may receive both in the same year if you change jobs.
Frequently asked questions
What is a P45?
A document your employer gives you when you leave a job, showing your pay and tax for the year so far and your tax code, so your next employer can tax you correctly.
Do I need a P45 to start a new job?
It helps, because it lets your new employer use the right tax code immediately. Without it, they use a starter checklist and you may be on an emergency code for a while.
Can I get a replacement P45?
No. Employers cannot reissue a P45. Your new employer can use a starter checklist instead, and your Personal Tax Account shows your pay and tax.
What is the difference between a P45 and a P60?
A P45 is given when you leave a job, while a P60 is given at the end of the tax year while you are still employed.