You've just left a job, and someone hands you a form called a P45. Or you run a small business and an employee is leaving, so now you have to produce one. Either way, you want to know what it's actually for and what to do with it.
A P45 is the document that records your pay and tax for the year so far when you leave a job. It's how your tax position follows you from one employer to the next, so you don't end up paying the wrong amount of tax in your new role.
This guide explains what's on a P45, when you should get one, how it differs from a P60, and what to do if you've lost yours. It's written for both employees and the employers who have to issue them.
What is a P45? {#what-is-a-p45-section}
A P45 is an official HMRC form your employer gives you when you stop working for them. It shows how much you've earned and how much income tax you've paid in the current tax year, up to the date you left.
It does one main job: it carries your tax details to your next employer so they can apply the right tax code from your first payday. Without it, you'll often start on an emergency tax code and may overpay for a while.
The "P45" name isn't an acronym. The "P" marks it as a PAYE form, and "45" is just HMRC's number for this form. It's been called that for decades.
A P45 comes in parts. Part 1 goes to HMRC. The rest go to you, and gov.uk is clear on what happens next: you keep Part 1A for your own records, and you give Parts 2 and 3 to your new employer.
What information is on a P45?
Every P45 shows the same core details, so once you've seen one you'll recognise the next. You'll find:
- Your full name and National Insurance number
- Your employer's PAYE reference
- Your leaving date
- Your tax code when you left (for many people on the standard allowance this is 1257L for 2025/26)
- Your total pay in this tax year up to your leaving date
- The total income tax deducted in this tax year up to your leaving date
- Whether student loan deductions should continue
When you get yours, it's worth a quick check. Make sure your name and National Insurance number are right, the leaving date matches reality, and the tax code and figures line up with your final payslip. If something looks wrong, ask your former employer to confirm the details before you start your new job.
When should I get a P45?
You should get a P45 any time you stop working for an employer who's been paying you through PAYE. That covers leaving a permanent job, finishing a fixed-term contract, being made redundant, retiring, or being dismissed. The reason you leave doesn't change the obligation.
gov.uk says your employer "should give you a P45" when you leave. In practice, most employers produce it when they run the payroll that includes your final pay, so you'd usually receive it within days of that run rather than instantly.
You won't get a P45 if you're simply changing roles, teams, or sites within the same company. The form is only triggered when your employment with that employer actually ends.
If you hold two jobs at once and leave one, you'll only get a P45 from the employer you're leaving. The other job carries on as normal.
What's the difference between a P45 and a P60?
Both forms deal with your pay and tax, which is why people mix them up. The simplest way to remember it: a P45 is for leaving, a P60 is for staying.
| Feature | P45 | P60 |
|---|---|---|
| When you get it | When you leave a job | After each tax year ends |
| Who gets it | Employees who are leaving | Employees still employed on 5 April |
| What it covers | Pay and tax up to your leaving date | Pay and tax for the whole tax year |
| Format | Parts 1, 1A, 2 and 3 | A single document |
| What you do with it | Keep Part 1A, give Parts 2 and 3 to your new employer | Keep it for your records |
You can end up with both in the same year. If you leave one job partway through the year, you get a P45. If you're employed by someone else on 5 April, that employer gives you a P60 covering your time with them. Your employer must give you your P60 by 31 May after the end of the tax year.
If you have more than one job at the same time, you'll get a P60 from each employer at year end, and a P45 only from a job you actually leave.
Both are worth keeping. You may need them years later for a mortgage application, a benefits claim, or a tax query.
Do I need a P45 if I'm self-employed?
If you're a sole trader, you don't issue yourself a P45. P45s are for employees, and you're not an employee of your own sole-trader business.
But if you left a job to go self-employed, hang on to the P45 from that job. When you file your first Self Assessment tax return, you'll use it to report the employment income and tax you'd already had deducted through PAYE that year. HMRC then works out your total bill across both your employment income and your self-employed profits.
A couple of practical points. Your earlier employment earnings count towards your total income for the year, so they affect which tax bands your self-employed profits fall into. And the National Insurance you pay as a sole trader (Class 4) is worked out separately from the Class 1 National Insurance you paid as an employee. You can see the current self-employed rates on the self-employed tax calculator.
If you run a limited company and take a salary, you're an employee of your own company, so the usual PAYE rules apply. Whether a P45 is needed when you stop taking a salary depends on whether you're coming off the payroll or just pausing pay, so it's worth checking with your accountant.
What if my new employee doesn't have a P45?
Plenty of new starters won't hand you a P45, and that's normal. It happens when it's their first job, when they're keeping another job alongside this one, when they've been self-employed, after a career break, or when their last job ended in an earlier tax year.
When there's no usable P45, ask the employee to complete a starter checklist (the form that replaced the old P46). gov.uk also tells you to use the starter checklist if the employee left their last job before 6 April 2025, because a P45 from an earlier tax year is out of date.
The checklist asks the employee to pick the statement that fits them:
- Statement A: this is their first job since 6 April and they haven't been getting taxable benefits or a pension.
- Statement B: this is now their only job, but they've had another job or taxable benefits since 6 April.
- Statement C: they have another job or receive a pension.
You then use HMRC's tool to work out the correct tax code and starter declaration from their answers. The checklist also captures whether student loan deductions apply and which plan they're on, so you can deduct the right amount.
What is emergency tax without a P45?
If you start a job without giving your employer a P45 or completing a starter checklist, they don't have enough information to set your code properly, so you'll usually be put on an emergency tax code. gov.uk describes this as normal and temporary.
You can spot an emergency code by what's tacked onto the end of it: W1 if you're paid weekly, M1 if you're paid monthly, or X if your pay dates vary (you might also see "NONCUM" on your payslip). On an emergency code, your tax is worked out only on what you're paid in that week or month, rather than across the whole year.
The standard personal allowance for 2025/26 is £12,570, taxed via code 1257L, with the basic rate of income tax at 20%. On a non-cumulative emergency version of that code, you don't get the benefit of any unused allowance built up earlier in the year, so you can temporarily pay more tax than you should.
Illustrative example. Suppose you start a job in September on £30,000 a year, paid £2,500 a month, and you're put on 1257L M1.
- Monthly slice of the personal allowance: £12,570 ÷ 12 = £1,047.50
- Taxable pay that month: £2,500 - £1,047.50 = £1,452.50
- Income tax at 20%: £290.50 for the month
Because the M1 code ignores the allowance you didn't use between April and August, you pay more in those first months than a cumulative code would charge. Once HMRC has the right information, your code is corrected and any overpaid tax is repaid.
To sort it out, give your employer your P45 or complete the starter checklist, and check your take-home pay on your first payslip. You can also check your tax through your Personal Tax Account. HMRC normally squares up any over- or underpayment after the tax year ends.
Can I get a replacement P45?
No. This is one of the most common questions, and the answer is firm: gov.uk states that if you've lost your P45, "you cannot get a replacement." Only your original employer ever issued one, and there's no duplicate to request from HMRC.
That doesn't leave you stuck. You have a few options:
- Use a starter checklist. Your new employer can set you up from the checklist instead of a P45.
- Check your final payslip. It shows your tax code and your year-to-date pay and tax, which is much of what a P45 contains.
- Use your Personal Tax Account or the HMRC app. You can view your pay and tax details for recent tax years there.
You won't be penalised for losing a P45. The starter checklist exists precisely so a missing P45 never stops you starting a new job.
How do employers issue a P45?
For most employers, payroll software handles this. You mark the employee as a leaver, enter their leaving date, run their final pay, and the software produces the P45 and reports the leaver to HMRC through your Full Payment Submission (FPS) under Real Time Information.
If you have fewer than 10 employees and don't use commercial software, you can use HMRC's Basic PAYE Tools to run payroll and produce P45s for free. Many businesses simply outsource the whole job, so the leaver is processed and reported on their behalf.
A P45 doesn't have to be printed. A clearly formatted digital PDF is fine, as long as it carries all the required information and the employee can print it if they want a paper copy.
Whatever route you use, the principle is the same: process the leaver promptly, check the figures, report it to HMRC on time, and give the employee Part 1A to keep and Parts 2 and 3 for their next employer.
Running payroll while also running a business is exactly where small mistakes creep in. If you'd rather hand it over, book a free 20-minute call with a Zmartly accountant and we'll take payroll, leavers, and P45s off your plate. You can also see how we support small businesses day to day.
FAQs
What is a P45?
A P45 is an official HMRC form your employer gives you when you leave a job. It shows how much you've earned and how much income tax you've paid in the current tax year up to your leaving date. You keep Part 1A and give Parts 2 and 3 to your new employer so they can apply the correct tax code.
What's the difference between a P45 and a P60?
A P45 is issued when you leave a job and covers your pay and tax up to your leaving date. A P60 is issued to employees who are still employed on 5 April and covers the whole tax year. Your employer must give you your P60 by 31 May after the tax year ends.
Can I get a replacement P45?
No. gov.uk confirms you cannot get a replacement P45 if you've lost yours. Instead, complete a starter checklist with your new employer, check your final payslip, or view your pay and tax details for recent tax years through your Personal Tax Account or the HMRC app.
What do I do if I don't have a P45 for my new job?
Your new employer will ask you to complete a starter checklist, the form that replaced the P46. Pick the statement that matches your situation and confirm any student loan details. Your employer uses your answers to work out the right tax code.
Do I need a P45 if I'm self-employed?
As a sole trader you don't issue yourself a P45, because you're not an employee of your own business. If you left a job to go self-employed, keep that job's P45, as you'll need the figures for your first Self Assessment tax return.
What is emergency tax and how do I avoid it?
Emergency tax applies when your employer doesn't have your P45 or a completed starter checklist, so they use a temporary code ending in W1, M1 or X. That works out tax on each pay period alone, which can mean overpaying for a while. To avoid it, give your employer your P45 or complete the starter checklist promptly. HMRC squares up any over- or underpayment once it has the right details.
