Emergency tax code: what it is and how to fix it

Published Wednesday 19 August 2026

Table of contents

• What is an emergency tax code?
• How do I know if I'm on an emergency tax code?
• Why am I on an emergency tax code?
• How do I fix an emergency tax code?
• Will I get a refund from emergency tax?
• Simplify PAYE tax codes with Xero
• FAQs on emergency tax code

Key takeaways

• An emergency tax code is a temporary code HMRC uses when it doesn't have enough information about your employment or income. It’s usually shown with W1 or M1 suffixes, and can reduce your take-home pay until corrected.
• Fix it by providing a P45 from your previous employer or completing a starter checklist. HMRC will send a corrected tax code notice to your employer, usually within a few days.
• If you overpay tax due to an emergency code, the refund comes through your next pay run once the correct code is applied, or via a P800 from HMRC if payroll can't adjust it.
• Collecting starter documents early and filing Full Payment Submissions on time prevents most emergency tax issues before they start.

What is an emergency tax code?

An emergency tax code is a temporary code HMRC assigns when it doesn't have enough information about your tax circumstances. Figuring out the correct tax code can take up to 35 days from when you start a new job. While the emergency code is in place, you may pay more tax than usual – though any overpayment will be refunded once the correct code is applied.

An emergency tax code usually ends with W1 or M1, which signifies whether you're paid weekly or monthly. Sometimes you’ll see X if pay is irregular.

Common emergency tax codes

The codes below are the ones you're most likely to see on a payslip when emergency tax applies.

• 1257L W1 or 1257L M1: Your Personal Allowance is applied on a non-cumulative basis, meaning you get one month's or one week's worth of tax-free pay, not the full year's allowance spread across each pay period.
• BR W1 or M1: All your pay is taxed at the basic rate (20%) with no Personal Allowance applied to this job.
• 0T W1 or M1: No Personal Allowance is applied and your pay is taxed at the relevant rates without any tax-free amount.
• S1257L W1 or M1: The Scottish emergency code, applying Scottish tax rates on a non-cumulative basis.
• C1257L W1 or M1: The Welsh emergency code, applying Welsh tax rates on a non-cumulative basis.

Understanding these codes helps you spot when you're on emergency tax and take action quickly. The sooner you identify the issue, the faster you can correct it and recover any overpaid tax.

How much tax do you pay on an emergency code?

The amount of tax you pay on an emergency code depends on which code your employer applies. Each code treats your Personal Allowance differently, which directly affects your take-home pay.

Here's what each common emergency code means for your tax deductions:

• 1257L W1 or M1: You receive one week's or one month's worth of your Personal Allowance (roughly £242 per week or £1,048 per month in the 2026/27 tax year) rather than the full annual amount spread cumulatively. You may overpay tax if you had unused allowance from earlier in the year.
• BR: All your pay from this job is taxed at the basic rate of 20% with no Personal Allowance applied. This is common for second jobs or where HMRC has no information about your circumstances.
• 0T: No Personal Allowance is applied and your pay is taxed at 20%, 40%, or 45% depending on the amount. This typically results in the highest emergency tax deductions.

Once your correct code is in place, any overpayment is refunded automatically through payroll or via a P800 from HMRC.

How do I know if I'm on an emergency tax code?

There are a few main places to look to see if you’re on an emergency tax code:

• Your payslip: Check the tax code field. A code like 1257L W1 or 1257L M1 confirms emergency tax is being applied.
• Your HMRC personal tax account: Log in at gov.uk to see your current tax code and which employer it's linked to.
• The HMRC app: Download the app to view your tax code and check for any discrepancies against what your employer is using.
• A P45 from your previous employer: If the code on your payslip doesn't match the code on your P45, your employer is likely using a temporary emergency code.

Why am I on an emergency tax code?

Emergency codes often appear when HMRC doesn't have complete information about your employment or tax situation. While your situation is unclear, the emergency tax code prevents you from underpaying your tax, even if it means overpaying in the short term.

Emergency codes usually appear when you:

• Start a new job and your employer doesn't receive a P45 from your previous employer or you don't complete starter details in time for the first payroll.
• Move from self-employment into PAYE employment, as HMRC needs time to update your records and issue a new tax code.
• Start or change taxable company benefits, such as a company car, health insurance, or other benefits in kind that affect your tax code calculation.
• Begin receiving the state pension or take a pension withdrawal, which can trigger a code change that doesn't reach your employer in time.
• Have more than one job or switch jobs quickly within the tax year, causing delays in HMRC processing your new employment details.
• Have a recent change in personal details that hasn't yet reached payroll, such as a change of address or marital status that affects your tax position.

These situations create information gaps that HMRC fills temporarily with an emergency code. Once HMRC receives the missing details, it issues the correct code to your employer. For small business owners managing payroll, understanding payroll obligations can help you to resolve these issues more quickly.

What if I started a job more than 35 days ago?

HMRC usually corrects an emergency tax code within 35 days of you starting a new job. If you've been in your new job for longer than that and you're still on an emergency tax code, HMRC may not have received the information it needs to issue the correct code automatically.

At this point, contact HMRC directly rather than waiting. You can do this through your HMRC personal tax account at gov.uk, the HMRC app, or by calling the HMRC income tax helpline. Have your National Insurance number, your employer's PAYE reference, and your start date ready. HMRC will update your record and issue a new code to your employer, usually within a few days.

Emergency tax on pension withdrawals

From April 2025, HMRC automatically updates tax codes when you first start receiving a private pension, which has reduced emergency coding in many cases. However, if you take a one-off flexible withdrawal, your pension provider may still apply an emergency tax code on a Month 1 basis if HMRC hasn't yet issued the correct code for that payment.

This can result in a significant overpayment, particularly if you're taking a one-off lump sum. For example, a single withdrawal of £20,000 may be taxed as though your annual income is £240,000, pushing it into higher tax bands.

To reclaim overpaid tax on a pension withdrawal, you can submit one of the following forms to HMRC:

• Form P55 if you've taken a partial withdrawal and aren't taking regular payments
• Form P53Z if you've taken your entire pension pot and have other income sources
• Form P50Z if you've taken your entire pension pot and have no other income

HMRC will process your claim and issue a refund, typically within 30 days. Alternatively, HMRC reconciles the overpayment automatically at the end of the tax year via a P800 calculation.

How do I fix an emergency tax code?

Fixing an emergency tax code requires clear communication between you, your employer, and HMRC.

Steps for employees

Taking these actions ensures HMRC has the information it needs to issue the correct code and your employer can apply it promptly.

1. Check your code on your payslip and compare it to any P45 from your previous employer to see if the codes match. If your payslip shows W1/M1 suffixes, that's a clear sign emergency tax is being applied and you need to act.
2. Give your P45 to your new employer or complete the HMRC starter checklist if you don't have a P45, ensuring you select the correct starter declaration. The declaration you choose tells HMRC whether this is your only job, your first job since 6 April, or a second job alongside another, which directly determines the code you receive.
3. Update HMRC with any changes to your circumstances, including address changes, benefits, second jobs, or pension income that might affect your code. You can do this quickly through your HMRC personal tax account at gov.uk without needing to call.
4. Ask your employer when the P6 code notice will be applied to payroll so you know when to expect the correction. Most employers apply code notices in the next available pay run after receiving them from HMRC.
5. Check the next payslip for the automatic correction or refund, which should appear once the correct code is in place. If the refund doesn't appear after two pay periods, follow up with your employer to confirm the updated code has been entered in the payroll system.

Steps for employers and payroll admins

Following these setup and filing steps prevents or clears emergency codes in Real Time Information (RTI) submissions, keeping your team's pay accurate.

1. Collect a valid P45 or a completed starter checklist with the correct starter declaration from every new employee before their first pay run. If neither arrives in time, use the information available to apply the most appropriate emergency code rather than leaving the field blank, which can cause further delays.
2. Enter the initial tax code from the P45 or starter checklist in your payroll system and select the right basis: cumulative or W1/M1, based on the information you've received. Setting the wrong basis is one of the most common payroll errors and can result in either under- or over-deduction of tax from the employee's first pay period.
3. Send the Full Payment Submission (FPS) on or before payday to prompt HMRC to issue code notices quickly if adjustments are needed. Late FPS submissions delay HMRC's ability to issue the correct code, which means the employee stays on emergency tax for longer.
4. Apply P6 or P9 notices as they arrive from HMRC and check for automatic refunds in the next run, ensuring you don't delay corrections. Your payroll software will calculate the year-to-date adjustment automatically once you enter the new code and switch the basis to cumulative.
5. Keep benefits and pension details current in your payroll system to avoid reversion to 1257L W1/M1 or 0T when circumstances change. When an employee starts a new benefit in kind, for example, HMRC will issue a revised code, and applying it promptly prevents the employee from being over-taxed in subsequent pay periods.

Will I get a refund from emergency tax?

Overpaid tax due to an emergency code can be refunded through two main routes, depending on your employment status and timing.

Through payroll

When your employer receives the correct tax code from HMRC, they apply it to your next pay run and automatically refund any overpayment. This is the fastest route and happens without you needing to contact HMRC directly. Your payslip will show the adjustment, typically as a negative tax amount or a note indicating a refund. Refunds usually appear within one to two pay runs after the correct code is applied.

From HMRC

If your employer cannot adjust the overpayment through payroll – for example, if you've left the job or the tax year has ended – HMRC will send you a P800 calculation. This calculation shows the overpayment and explains how you'll receive the refund, either by cheque, bank transfer, or adjustment to your tax code for the following year. The refund can take several weeks or months after the tax year ends.

Simplify PAYE tax codes with Xero

Xero helps you keep payroll accurate with clear employee records and automated tax calculations, so emergency tax codes are less likely to appear in the first place. Try Xero and see how much easier payroll can be.

Get one month free.

FAQs on emergency tax code

This section answers common questions about emergency tax codes, helping you understand when they apply, how to fix them, and how to prevent them in future.

How should an employer handle a new starter with no P45 to avoid an emergency tax code?

If a new employee doesn't have a P45, ask them to complete the HMRC starter checklist before their first pay run so HMRC can issue the right code.

Which emergency tax codes should employers expect for new hires?

Employers typically see 1257L W1 or 1257L M1 for new starters when HMRC applies the standard Personal Allowance on a non-cumulative basis. BR W1/M1 appears if the employee has another job or HMRC needs to tax all pay at the basic rate without applying a Personal Allowance. 0T W1/M1 appears when no Personal Allowance is applied, often if the employee's total income exceeds the Personal Allowance threshold or HMRC needs more information. Scottish and Welsh employees may see S1257L W1/M1 or C1257L W1/M1, applying regional tax rates.

When will HMRC send a P6 or P9 after the first Full Payment Submission?

HMRC typically issues a P6 (an in-year tax code change notice) or P9 (a new tax year tax code notice) within a few days to two weeks after receiving the first Full Payment Submission. If you don't receive a code notice within two weeks, check that the FPS was submitted correctly and contact HMRC to confirm they have the employee's details.

How do employers process an emergency tax rebate through payroll?

When you receive a corrected tax code from HMRC, enter it into your payroll system and set the basis to cumulative (not W1/M1). The payroll software calculates the year-to-date tax the employee should have paid and compares it to the amount already deducted. If the employee has overpaid, the system automatically refunds the difference in the next pay run, showing it as a negative tax amount or refund on the payslip.

What should employers do if a corrected code arrives after payroll cut-off?

If a corrected tax code notice arrives after you've processed payroll for the current period, apply the new code in the next pay run – there’s no need to reprocess the previous payroll.