Your P45 Explained

A P45 is what your employer gives you when you leave a job. It shows your leaving date, your tax code, and your pay and tax from that job so far in the tax year (6 April to 5 April). Give it to your new employer (or to Jobcentre Plus, if you're not moving straight into another job) to help them tax you correctly from your very first payslip, rather than on an emergency code. HMRC withdrew pre-printed paper P45 stationery in 2019. Today's P45s are generated by payroll software, but the fields and layout below are what every P45 still contains.

If you're checking a P45 partway through the tax year, you might also want to see Your P60 Explained, the equivalent year-end summary you'd get instead, if you'd stayed in the same job through to 5 April. And if handing over your P45 late meant a spell on emergency tax, see Your P800 Explained for how that kind of overpayment usually gets sorted out.

A P45 isn't one document, it's four copies of the same information, split across Parts 1, 1A, 2, and 3, each going to someone different. Parts 1, 1A, and 2 are identical; Part 3 carries a few extra boxes for your new employer to complete. In practice you'll usually only ever see Parts 1A, 2, and 3. Part 1 goes straight from your old employer to HMRC, so it may never actually reach you.

Click a box on the certificate below, or open any item in the list, to see what it means. Pick a part above to see how its own copy is labelled.

P45: Details of employee leaving work

Part 1A: copy for employee

Employer and employee details

1Employer PAYE reference456/CD78901 2National Insurance numberQQ 12 34 56 C 3Title, surname, first name(s)TitleMSSurname or family nameTAYLORFirst name(s)SAM

Leaving this job

4Leaving date19 09 2026 5Student Loan deductionsStudent Loan deductions to continue 6Tax code at leaving date1257LWeek 1/month 1 7Total pay and tax to dateWeek number—Month number6Total pay to date£24,500.00Total tax to date£2,830.60 8This employment pay and tax (if different)Total pay in this employment—Total tax in this employment—

Other details

9Works/payroll number and department or branchEMP-1180 · Warehouse 10GenderMaleFemale 11Date of birth14 03 1994 12Employee's private address42 Anywhere Road, Sometown, ZZ1 1ZZ

Employer certification

13Employer certificationNorthfield Logistics Ltd, 8 Harbour Way, Portswick, CD3 4EF

1Employer PAYE reference

What it is: A unique reference number HMRC uses to identify the employer you're leaving, the same reference that appears on your payslips from that job.

Why it matters: Your new employer (or HMRC) uses this to link your P45 back to the exact PAYE scheme it came from, so your pay and tax history connects to the right employer record.

What to check: Nothing to check for accuracy, just useful to have to hand if you ever need to query this employment with HMRC.

2National Insurance number

What it is: Confirms which National Insurance record your pay and contributions are linked to.

Why it matters: Your new employer uses it to carry on reporting your pay under the correct NI record. See National Insurance Explained.

What to check: Make sure it matches the NI number on your other documents (payslips, P60, NI card), errors here can cause mismatches with your HMRC record.

3Title, surname, first name(s)

What it is: Your name, as held on your employer's payroll record, split across three separate lines, matching the real form: title, surname, first name(s).

Why it matters: Confirms this P45 belongs to you, which matters once it's handed to a new employer or used as evidence elsewhere.

What to check: Check the spelling matches your other records, a mismatch here is a common, easily-missed source of payroll errors.

4Leaving date

What it is: The last day of employment with this employer.

Why it matters: This date sets exactly which part of the tax year the pay and tax figures on this form cover, everything from 6 April up to this date.

What to check: Make sure it matches your actual last working day. An incorrect leaving date can throw off the pay and tax figures your new employer bases your tax code on.

5Student Loan deductions

What it is: A single tick confirming whether Student Loan deductions should continue with your next employer. The same box covers a Postgraduate Loan too. Unlike your P60, no repayment amount is shown here at all, since these deductions aren't cumulative in the way pay and tax are.

Why it matters: It's the only thing that tells your new employer whether to keep taking loan repayments from your pay from day one, rather than waiting to be told separately. See Student Loan Repayments Explained for how much that actually is.

What to check: If you don't have a student or postgraduate loan but this box is ticked, or the other way round, tell your new employer's payroll team straight away. Otherwise the wrong deductions could start from your very first payslip.

6Tax code at leaving date

What it is: The tax code your old employer was using for you on your last day, for example 1257L, plus a flag for whether it was being applied cumulatively or on a "week 1/month 1" (non-cumulative) basis.

Why it matters: Your new employer normally carries this code forward until HMRC tells them otherwise. See Understanding Your Tax Code.

What to check: See Understanding Your Tax Code to check it looks right for your situation, especially if box 7 is blank, since that means week 1/month 1 applied and your pay wasn't being taxed cumulatively.

7Total pay and tax to date

What it is: The week or month number shows how far into the tax year your employer's payroll had run. Only one of the two is used, depending on whether you're paid weekly or monthly. Below that, your cumulative taxable pay and Income Tax paid from 6 April up to your leaving date, taken from your employer's payroll record. All of it is left blank instead if a week 1/month 1 tax code applied, since those figures aren't run cumulatively.

Why it matters: Your new employer uses this as the starting point for continuing your Income Tax calculation cumulatively through the rest of the tax year, rather than starting from zero.

What to check: Compare it against your own payslips from this job, if you kept them. If it looks obviously wrong, flag it with your old employer before starting your next job.

8This employment pay and tax (if different)

What it is: Only filled in if the pay and tax figures for this specific job differ from the cumulative total in box 7, for example, after a mid-year tax code change. Blank, as here, simply means box 7 already is the figure for this job.

Why it matters: It's a safeguard against a hidden mismatch. Without it, a mid-year change could make the cumulative total in box 7 look inconsistent with what you'd expect from this job alone.

What to check: If these boxes are blank, there's nothing extra to check as box 7 already covers it.

9Works/payroll number and department or branch

What it is: Your employer's own internal reference for you, and, where relevant, which department or branch you worked in.

Why it matters: Purely for the employer's own records. It doesn't feed into any tax calculation.

What to check: Optional field. It's completely normal for this to be blank.

10Gender

What it is: A tick box for male or female, a legacy field HMRC's payroll systems still require internally.

Why it matters: It has no effect on your tax calculation. Income Tax and National Insurance in the UK are gender-neutral. It's retained purely as an older administrative field.

What to check: Nothing to check for tax purposes. This has no bearing on how much tax you pay.

11Date of birth

What it is: Your date of birth, as held on your employer's payroll record.

Why it matters: Used to confirm your identity on HMRC's systems, and relevant to a handful of age-related thresholds elsewhere in the tax system, like State Pension age.

What to check: Make sure it's correct as an error here can cause mismatches with your HMRC record, similar to an incorrect National Insurance number.

12Employee's private address

What it is: Your home address, as held by your old employer.

Why it matters: Mainly there for your new employer's reference. It doesn't feed into the tax calculation itself.

What to check: Worth checking it's up to date if you've moved recently, since it's what your old employer has on file.

13Employer certification

What it is: Your former employer's declaration that boxes 1 to 11 are correct, along with their name and address.

Why it matters: Confirms which employer this P45 actually came from. This only matters if you've had more than one job, or need to provide it as evidence elsewhere.

What to check: Make sure it's the employer you actually expect it from, especially if the company's trading name has changed.

This page explains what a P45 shows and is not personalised advice; see the disclaimer. Field layout described here reflects the standard P45 format for the 2026/27 tax year; always refer to your own certificate as the source of truth for your figures.