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P45 Form UK: What It Is & Why It Matters

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Part ofHMRC Forms UK

Written by Brad Askew Solicitor (non-practising)
Brad is on the roll of solicitors of England & Wales but does not hold a practising certificate and does not provide legal advice.
Updated June 2026 · England & Wales
When you leave a job in the UK, your employer is required to give you a P45. It sounds like a bit of bureaucratic admin, but this small document actually plays a surprisingly important role in your working life. It tells HMRC and your next employer what tax you've already paid in the current tax year, which in turn affects how much tax is taken out of your next payslip. Getting it wrong, or losing it entirely, can mean you end up on an emergency tax code and paying more than you should. In this guide I'll walk you through what a P45 is, what information it contains, why each part matters, and what to do if yours has gone astray.

What this document is

A P45 is the certificate your employer hands you when your employment with them ends, whether that's because you resigned, were dismissed, or reached the end of a fixed-term contract. It's officially titled 'Details of employee leaving work' and it summarises your pay and tax position up to the date you stopped working for that employer.

The form comes in several parts: one stays with your old employer for their records, and the rest are given to you. When you start a new job, you hand the relevant sections to your new employer so they can set up your payroll correctly.

If you're moving onto Jobseeker's Allowance or another benefit, you give the form to Jobcentre Plus instead. The key purpose is continuity. Without a P45, your new employer has no way of knowing what tax code you should be on or how much you've already earned in the tax year, which is why it matters so much for making sure your take-home pay is calculated correctly from day one.

How to use this document

  1. Check you receive it on leaving. Your employer should issue your P45 automatically when you stop working for them, typically with your final payslip. If it doesn't arrive within a reasonable time after your last pay date, chase your former HR or payroll team directly. They have a legal duty to provide one.
  2. Verify the details are correct. Look carefully at your name, National Insurance number, tax code, leaving date, and the figures for total pay and tax paid in the current tax year. Even small errors can cause problems later, so flag anything that looks wrong to your previous employer straight away and ask for a corrected version.
  3. Keep Part 1A safe for your records. Part 1A is yours to keep and should be stored somewhere you can find it again. You may need it when completing a Self Assessment tax return, claiming a tax refund, or sorting out any HMRC queries down the line. A scanned digital copy is a sensible backup.
  4. Hand Parts 2 and 3 to your new employer. When you start a new job, give Parts 2 and 3 to your new payroll team as early as possible, ideally before your first pay day. This allows them to apply the correct tax code so you don't end up being taxed at an emergency rate while HMRC catches up.
  5. Contact HMRC if you can't get a replacement. If your previous employer has gone out of business or simply won't respond, HMRC can confirm your pay and tax details to your new employer directly. You can reach them through your Personal Tax Account on gov.uk or by calling the income tax helpline.

Common questions

If you're dealing with this kind of situation, speak to an experienced legal adviser who can walk you through it — from £89.

Common questions

Q When should I expect to receive my P45?
Your employer should give you your P45 on or shortly after your final day of employment, usually at the same time as your last payslip. There's no fixed statutory deadline to the day, but it should arrive without unreasonable delay. If weeks have passed and nothing has turned up, contact your former payroll team. Persistent failure to issue one can be reported to HMRC.
Q What happens if I start a new job without a P45?
You can still start work, but your new employer will likely put you on an emergency tax code until they receive accurate information. This often means paying more tax than you owe in the short term. You'll usually be asked to complete a starter checklist so payroll can estimate your tax position until HMRC confirms the correct code. Any overpaid tax is refunded through your later payslips.
Q Can I get a copy of an old P45?
Employers are not obliged to reissue a P45 once it has been given out, though many will provide a duplicate or a statement of earnings as a courtesy. If you cannot get one from your previous employer, your Personal Tax Account on gov.uk shows your pay and tax history, which is usually enough for most purposes, including Self Assessment or checking your tax code.
Q Do I need a P45 to claim a tax refund?
Not necessarily. HMRC can usually calculate refunds from the information submitted by employers through PAYE, so a missing P45 is rarely a blocker. However, having Part 1A makes the process smoother and faster, particularly if you're claiming a refund after leaving the UK or stopping work partway through the tax year using a form such as the P85.
Q What is the difference between a P45 and a P60?
A P45 is issued when you leave a job and summarises pay and tax for that employment only. A P60 is issued at the end of each tax year by your current employer and summarises everything you earned and paid in tax through them during that year. You'll usually receive a P60 each April if you're still employed on 5 April.
Q What should I do if my P45 shows the wrong tax code?
Tax codes can appear wrong for various reasons, from benefits in kind being miscalculated to HMRC not having up to date information. The first step is to check your code through your Personal Tax Account, where you can also update details directly. If something looks off, contact HMRC to correct it. Your new employer will then be told the right code to apply.
Q Does a P45 still exist now that payroll is digital?
Yes. Although payroll reporting to HMRC is now done digitally in real time, the P45 remains the standard document given to employees when they leave a job. Some employers provide it electronically rather than on paper, which is perfectly acceptable. What matters is that you receive the information and can share the relevant parts with your next employer.
If you're dealing with this kind of situation, speak to an experienced legal adviser who can walk you through it — from £89.

Sources

This guide is based on primary UK law and official guidance.

Brad Askew, Solicitor (non-practising)

Written & reviewed by

Brad Askew Solicitor (non-practising)

Brad is on the roll of solicitors of England & Wales but does not hold a practising certificate and does not provide legal advice. LegalDocuments.co.uk is not a law firm and does not provide regulated legal advice.

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Legal disclaimer
This article is for general information only. It is a tool to help you find your way — not legal advice, and not a substitute for speaking to a qualified adviser about your situation.