If you have changed jobs and your first payslip shows emergency tax, gather your P45, final payslip from your old job, first and latest payslips from the new job, employment dates, and the information HMRC currently holds about both employments before trying to fix it. These records help establish whether your new employer is missing information, HMRC has not yet matched the jobs correctly, or the tax code is correct but has not reached payroll yet.
This guide is for UK employees taxed through PAYE during the 2026/27 tax year. Emergency tax after a job change is often temporary, but it is still worth checking the underlying records because the same symptoms can also be caused by an old employment remaining open, incorrect income estimates, a missing P45, another job or pension, or taxable benefits.
Contents
- What emergency tax after changing jobs means
- Records to gather before contacting anyone
- How to tell whether payroll or HMRC needs to act
- What to do if you do not have a P45
- How long a new-job tax-code correction can take
- How overpaid emergency tax is refunded
- Common mistakes after changing jobs
What Emergency Tax After Changing Jobs Means
Under normal cumulative PAYE, your tax calculation can take account of your taxable pay and tax already deducted earlier in the tax year. An emergency code generally calculates the current pay period on a non-cumulative basis instead.
HMRC says an emergency tax code normally ends in W1, M1 or X. Some payroll systems display NONCUM. For the 2026/27 tax year, HMRC's employer guidance lists 1257L W1, 1257L M1 and 1257L X as emergency codes. You can check the current rules in HMRC's emergency tax code guidance.
The important detail is that 1257L by itself is not necessarily an emergency tax code. The W1, M1, X or NONCUM marker is what signals emergency or non-cumulative treatment.
If you recently changed employers, emergency treatment can occur because your new employer does not yet have your previous pay and tax information. HMRC says giving the new employer your P45 can help resolve this because the P45 contains information from the employment you have just left.
If you are unsure whether the code itself looks reasonable, see our separate guide to checking a wrong tax code on your payslip. The purpose of this article is narrower: assembling the evidence needed to fix a new-job problem efficiently.
Records to Gather Before Contacting Payroll or HMRC
Do not begin with a vague request such as “I have been emergency taxed.” Build a small PAYE file first. The aim is to compare what your former employer reported, what your new employer is deducting, and what HMRC currently believes.
| Record | What to check | Why it matters |
|---|---|---|
| P45 | Leaving date, pay to date, tax deducted, tax code and personal details | Transfers key current-year information from your previous employment |
| Final old-job payslip | Final pay date, taxable pay, tax deducted and year-to-date figures | Helps you compare the P45 with the final payroll figures |
| First new-job payslip | Tax code, taxable pay and Income Tax deducted | Shows which code the new employer originally operated |
| Latest new-job payslip | Current code and year-to-date pay and tax | Shows whether the position has already changed |
| Employment dates | Old leaving date and new starting date | Helps identify overlapping or incorrectly open employments |
| HMRC PAYE record | Employers shown, estimated income and tax code for each job | Reveals whether HMRC's underlying information is wrong |
| Other PAYE income | Second jobs and pensions | Your Personal Allowance may be allocated elsewhere |
| Benefits and adjustments | Company benefits, pensions and other coding adjustments | These can legitimately change your tax code |
1. Your P45
Your P45 is the most useful starting record. According to HMRC's P45 guidance, it includes your leaving date, total pay and tax from 6 April until you left, your tax code and personal details such as your National Insurance number.
If you have a paper P45, HMRC says you normally give Parts 2 and 3 to your new employer and keep Part 1A for your own records.
Before handing anything over, keep a copy or scan. Compare the pay and tax totals with your final payslip. If the P45 itself contains incorrect pay or tax figures, ask your former employer to correct it rather than expecting the new payroll department to repair somebody else's figures.
2. Your Final Payslip From the Previous Job
Keep the last payslip even after receiving the P45. It provides a second record of what actually happened in the final payroll.
Write down or highlight:
- the pay date;
- gross and taxable pay;
- Income Tax deducted;
- year-to-date taxable pay and tax, if shown;
- the tax code used;
- any final bonus, holiday pay or other taxable payment.
A final payment made after you technically stopped working can make a job change look more confusing than a simple “old salary ended, new salary began” timeline.
3. Your First and Latest Payslips From the New Job
Keep both rather than only the newest payslip. The first tells you how payroll initially set you up; the latest tells you whether HMRC or payroll has already corrected the position.
Look especially for W1, M1, X or NONCUM next to the tax code. Also record the Income Tax deducted and the year-to-date figures. If the code changes between payslips, note the exact pay period in which the change occurred.
4. Your Job Start and Leaving Dates
Make a simple two-line timeline:
- Old employer: final working date and final pay date.
- New employer: start date and first pay date.
Those dates are not always identical. An old employer can make a final payment after you have started the new job, and HMRC's records can temporarily show more than one employment.
5. A Snapshot of What HMRC Currently Shows
Sign in to Check your Income Tax for the current year or use the HMRC app. For 2026/27, the service covers the tax year from 6 April 2026 to 5 April 2027.
Check:
- whether your new employer appears;
- whether your previous employer is correctly marked as ended;
- the estimated annual income shown for each employment;
- the current tax code attached to each job;
- any pension income;
- company benefits or other items affecting the code.
HMRC specifically advises new starters to check that it has details of all current employers and that estimated income is reasonable. HMRC also notes that, where appropriate, only one employer should be using the standard 1257L allowance at one time.
6. Details of Other Jobs, Pensions and Taxable Benefits
An emergency-looking deduction is not always caused solely by the employer switch. Gather details of any second job, workplace or private PAYE pension, State Pension, or taxable employment benefit that could affect the code.
This matters because HMRC assigns tax codes across income sources. A code that seems unusually restrictive on your new salary may make more sense once another PAYE source is included.
Use the Records to Work Out Who Needs to Act
The fastest fix often comes from identifying whether the mismatch sits with the previous employer, the new payroll department or HMRC.
| What you find | Likely next step |
|---|---|
| Your P45 pay or tax totals are incorrect | Ask the previous employer for an amended P45 |
| You have a valid P45 but the new employer did not process it | Ask the new employer or payroll team to check the starter information it used |
| HMRC shows the old job as continuing when it ended | Update the employment details through HMRC's online service or app |
| HMRC shows an incorrect estimated salary | Update the estimated employment income with HMRC |
| HMRC shows the correct new tax code but the payslip still uses an older code | Ask payroll whether it has received and applied HMRC's latest coding notice |
| The payslip and HMRC both show the same code but you think its assumptions are wrong | Review and correct the jobs, pensions, income and benefits behind the HMRC code |
This distinction can save a great deal of circular calling. Your employer operates PAYE, but HMRC normally determines the tax code once it has the necessary information. Payroll generally cannot simply choose a different HMRC code because an employee asks for one.
What If You Do Not Have a P45?
If your former employer has not given you a P45, ask for it. If you have lost the P45, however, HMRC says you cannot obtain a replacement copy.
If you are starting the new job without a P45, use the HMRC starter checklist. The checklist replaced the old P46 process and helps the employer determine the initial PAYE treatment.
Before completing it, gather the information HMRC asks for, including:
- whether you have had another job or pension since 6 April;
- your National Insurance number;
- the start date of the new job;
- your student or postgraduate loan repayment plan, where relevant;
- details of certain taxable benefits or payments received since 6 April.
Answer the employment questions carefully. The declaration you make about previous or simultaneous work can affect the code used for your first payment.
If you have already received your first pay, HMRC says not to go back and use the starter checklist as a retrospective fix. Instead, use the current-year Income Tax service to check the code and correct information that is wrong or missing.
How Long Can a New-Job Tax-Code Correction Take?
Do not assume that one emergency-taxed payslip means the system has permanently failed. There is a reporting and coding cycle between the employer and HMRC.
HMRC says that when a new employer does not have the previous income and tax details, emergency treatment is usually temporary. HMRC will normally update the code after it receives the necessary information from the old and new employers, and this can take up to 35 days from when you start the job.
Separately, HMRC says new employment information should generally become visible in its online records within six weeks after your first payday.
If you correct information through HMRC and a new code is required, HMRC says it will tell you and your employer the new code within 15 working days.
Once the employer has the new code, HMRC says:
- monthly-paid employees should normally see it on the next or following payslip;
- weekly-paid employees should normally see it by the third payslip.
If HMRC already shows the new code but the expected payslips continue to use the old one, that is a useful point at which to raise the matter directly with payroll.
How Overpaid Emergency Tax Is Refunded
Emergency tax does not automatically mean you have overpaid. Depending on your total pay, earlier deductions and other income, you could have paid too much, the correct amount or too little.
If HMRC changes your code and has enough information to calculate your current-year position, it can work out the difference between the Income Tax you have paid and what should have been paid.
HMRC's guidance on overpaid and underpaid tax says that, where there has been an overpayment and sufficient information is available, HMRC can instruct the employer or pension provider to return the difference through pay when the new code is operated.
That means an unusually high net payment on a later payslip can sometimes be a PAYE correction rather than an error. Keep that payslip too, because it completes the audit trail.
If HMRC does not yet have the necessary income information, a refund may have to wait until those records arrive. If the position is still unresolved after the end of the tax year, HMRC normally reconciles PAYE records using the information reported by employers, pension providers and benefits offices.
Common Mistakes After Changing Jobs
Assuming 1257L must always be your correct code
For 2026/27 the standard Personal Allowance is £12,570, but not everyone is entitled to have that full allowance allocated to a particular job. Multiple jobs, pensions, taxable benefits, income level and previous tax adjustments can all affect the code.
Looking only at the tax deduction
A large deduction tells you that something happened. It does not tell you why. Always record the tax code, taxable pay and year-to-date pay and tax alongside the amount deducted.
Throwing away the first payslip once the second arrives
The sequence matters. Keep the first payslip, the payslip where the code changed and the first payslip after the correction. Together they show how the problem evolved.
Calling HMRC without checking its online record first
You may discover that HMRC already holds the correct code and the remaining issue is simply that payroll has not yet applied it. Conversely, payroll may be faithfully operating a code based on incorrect information held by HMRC.
Forgetting that the old employer can still make a payment
Holiday pay, commissions, bonuses, expenses or another final taxable amount can arrive after your official leaving date. Keep records of those payments rather than assuming every amount from the former employer is an error.
Ignoring another job or pension
A second PAYE source can completely change the interpretation of a tax code. Gather all current PAYE income before deciding that the new employer has deducted too much.
A Five-Minute Record Check Before You Escalate
- Find your P45 or confirm that you completed a starter checklist.
- Put your final old-job payslip beside your first and latest new-job payslips.
- Write down the old job's leaving date and the new job's start date.
- Compare the payslip tax code with the code in HMRC's current-year service.
- Check that HMRC has ended the old employment and recorded the new one correctly.
- Check the estimated annual income for the new job.
- List any second jobs, PAYE pensions, State Pension or taxable employment benefits.
- Keep any HMRC coding notice or online message showing that a code has changed.
Once those eight items are in front of you, the next action is usually much clearer: correct the P45 with the former employer, correct HMRC's underlying records, or ask the new payroll team to apply information HMRC has already issued.
Bottom Line
Emergency tax after changing jobs is often a temporary information problem rather than a permanent tax charge. The most useful records are your P45, final old-job payslip, first and latest new-job payslips, employment dates, and a current snapshot of what HMRC believes about your jobs and income.
Do not focus only on the number deducted. Reconstruct the information chain: what the old employer reported, what the new employer used and what HMRC currently holds. That tells you who needs to correct the problem and gives you a much stronger record if the first correction does not appear on the next payslip.
Educational note: This article provides general UK PAYE and Income Tax information and is not personalised tax advice. Your correct tax code and final liability can depend on your complete income, benefits, pensions and tax history.
