Emergency Tax Code UK: What It Means and How to Fix It in 2026/27

Last Updated on – 21-09-2026

An emergency tax code is used when PAYE needs to calculate Income Tax without using the employee’s complete year-to-date position.

This commonly happens after starting a new job, when previous pay and tax information is missing, or when certain pension or benefit circumstances change.

For the 2026/27 tax year, the standard UK Personal Allowance remains £12,570, and HMRC’s standard emergency code is based on 1257L.

The important difference is the W1, M1, X or NONCUM marker that makes the calculation non-cumulative.

This distinction matters. The old idea that emergency tax codes are connected with national emergencies, financial hardship, criminal investigations or HMRC blocking bank accounts is incorrect. They are simply part of the PAYE payroll system.

What Does an Emergency Tax Code Mean?

Ordinary PAYE is normally cumulative. Payroll looks at taxable pay and Income Tax already deducted since the start of the tax year and works out how much tax should have been paid up to the current payday.

Emergency tax works differently. A W1, M1 or other non-cumulative marker tells payroll to deal with the current pay period largely on its own rather than using the complete year-to-date calculation.

HMRC describes W1 as Week 1 and M1 as Month 1, while X is commonly used where pay dates vary. Some payroll software displays NONCUM instead.

Readers who want more detail about the underlying calculation can also see how a 1257L W1 tax code works or the site’s explanation of non-cumulative tax codes.

How Can Emergency Tax Affect a £2,500 Monthly Salary?

Consider an employee who had no taxable income from 6 April to September and starts a new job in October earning £2,500 per month.

For 2026/27, the standard Personal Allowance is £12,570, equivalent to roughly £1,048 per month for PAYE purposes.

If the employee is put on 1257L M1, only one month’s allowance is considered. Roughly £1,452 of the £2,500 payment is therefore taxable at the basic rate, producing approximately £290 of Income Tax.

With normal cumulative 1257L, the position is very different. By October, several months of unused Personal Allowance have accumulated.

Because the employee had no earlier taxable pay that tax year, the £2,500 October salary would be covered by the accumulated allowance and no Income Tax would normally be due on that payment.

The employee could therefore temporarily pay roughly £290 more tax because of the M1 basis.

This example assumes there was no earlier taxable income or relevant adjustment. Someone who had another job, pension, taxable benefits or previous tax deductions could get a different result.

How Can Someone Check Whether They Are on Emergency Tax?

The easiest place to start is the tax code shown on the payslip.

A person can also check the code through the HMRC app, their Personal Tax Account or HMRC’s current-year Income Tax service.

HMRC’s online service shows the tax code, estimated employment and pension income and whether the code has changed.

The most important part is usually the end of the code:

HMRC expressly states that if a code does not end in W1, M1, X or NONCUM, it is not an emergency tax code.

Anyone unsure whether their code suits their circumstances can also check the factors covered in Is My Tax Code Correct?.

Are BR, 0T and K Emergency Tax Codes?

This is one of the most confusing areas of PAYE.

BR and 0T are not automatically emergency tax codes. GOV.UK defines BR as a code under which all income from that job or pension is taxed at the basic rate, commonly because the taxpayer has another job or pension.

0T means no Personal Allowance is available through that particular source, which can happen when the allowance has already been used or an employer does not have sufficient information.

The emergency marker needs to be distinguished from the underlying tax code.

HMRC’s employer guidance confirms that W1 and M1 are emergency markers appearing at the end of a code. It also explains BR, 0T and K separately.

This distinction is especially important because a person can legitimately have BR on a second job without being “emergency taxed”.

Why Might Someone Get an Emergency Tax Code?

There is no application for an emergency tax code. An employer, pension provider or HMRC applies the appropriate PAYE treatment based on the information available.

HMRC specifically lists first jobs, missing P45s, returning after an employment break, moving from self-employment into employment and working for multiple employers among the circumstances in which a starter checklist may be needed.

Someone who cannot find an old form may find the explanation of what to do when they cannot get a copy of their P45 useful.

How Long Does an Emergency Tax Code Last?

For a new employee, HMRC says it will normally update the tax code after receiving the necessary information from the new and previous employers. This can take up to 35 days from the date the person starts the job.

A useful timeline is:

Employers must report new-starter information through a Full Payment Submission on or before the first payday.

There are two important exceptions to the idea that emergency codes always disappear quickly.

First, HMRC says that where a person has not paid enough tax, they can remain on the emergency code until the correct amount has been paid for the tax year.

Second, an emergency code introduced after starting to receive company benefits or the State Pension may remain until the end of that tax year, with a non-emergency code then applying in the new tax year.

How Can an Employee Get Off an Emergency Tax Code?

The correct solution depends on why the code appeared.

Employees should not invent a new code or simply ask payroll to substitute 1257L; employers are required to operate PAYE using the information and coding instructions available to them.

A practical sequence is:

1. Check the payslip and HMRC record. Confirm whether the code actually ends in W1, M1, X or NONCUM and check the employment and pension information HMRC holds.
2. Give the employer the P45 where available. A P45 contains previous pay and tax information that can help establish the correct PAYE position.
3. Complete the starter checklist if there is no P45. This allows the employer to select the appropriate starter declaration.
4. Update HMRC if the online information is wrong. Old employments, incorrect estimated income or missing pension information can affect the tax code.
5. Check subsequent payslips. HMRC says employers should normally apply a changed code by the next or following monthly payday, or by the third payday for weekly-paid employees.

What Do Starter Checklist Statements A, B and C Mean?

The current HMRC starter checklist makes the difference between the three declarations much clearer.

Statement B is therefore a common route into emergency Month 1 or Week 1 treatment.

Statement C is also why someone with a second job can receive BR. Crucially, BR alone is not the same thing as emergency tax.

Will HMRC Refund Emergency Tax Automatically?

Often, an in-year repayment can happen through payroll.

When HMRC has enough information, it can issue a corrected tax code. HMRC says that where too much tax has been paid and it has the required income information, it will calculate the difference and ask the employer or pension provider to refund it through pay.

For monthly employees, the corrected code should generally be used on the next or following payday after the employer receives it. For weekly payroll, HMRC says it should be used by the third payday.

If the issue is not fully resolved during the tax year, HMRC may reconcile the person’s record after 5 April. A P800 tax calculation may then show whether tax is owed or refundable.

HMRC says these calculations are normally sent between June and March of the following tax year.

Where a P800 says a refund is due, it explains how the money can be claimed. HMRC currently allows eligible repayments through its online service, Personal Tax Account, HMRC app or other specified routes.

Is It Necessary to Pay a Tax Refund Company?

No. HMRC explicitly says taxpayers can claim a tax refund themselves and do not need an agent to do it.

Commercial tax agents and refund companies may charge a fee for handling a repayment claim.

Using one is a personal choice, but taxpayers should understand the fee arrangement before authorising an agent.

For a straightforward emergency-tax overpayment, checking the PAYE record and dealing directly with HMRC can therefore avoid an unnecessary agent fee.

How Does Emergency Tax Work on Pension Withdrawals?

Pension withdrawals are one of the most important areas where emergency tax can produce a surprisingly large deduction.

HMRC’s 2026/27 employer guidance says that the taxable element of a pension-flexibility payment should generally be taxed using an emergency Week 1 or Month 1 code where the pension provider does not already have the appropriate current-year code.

Suppose someone flexibly withdraws £10,000 from a pension and £2,500 is tax-free, leaving £7,500 taxable.

If the person has no other taxable income for the entire tax year and qualifies for the full £12,570 Personal Allowance, their final Income Tax liability on that £7,500 may be nil.

However, if the pension provider initially operates a Month 1 emergency calculation, only approximately one month’s Personal Allowance and one month’s tax bands are available to that payment.

A significant amount of tax can therefore be deducted initially even though some or all of it may later be repayable.

The correct refund form depends on what happened to the pension pot.

HMRC confirms these distinctions in its current pension-repayment guidance.

The pension provider may instead correct tax through later payments where there is an ongoing pension PAYE source and HMRC subsequently provides an updated tax code.

Do Scotland and Wales Have Different Emergency Tax Codes?

The emergency principle is the same across the UK, but Scottish and Welsh taxpayers normally have a geographic prefix.

A Scottish employee receiving the standard £12,570 Personal Allowance might ordinarily have S1257L.

If operated on an emergency weekly basis, it could appear as S1257L W1. Scottish tax codes begin with S because Scottish Income Tax rates apply.

A Welsh taxpayer can similarly have C1257L, with C showing that Welsh Income Tax applies.

An emergency version could therefore appear as C1257L M1 or with another emergency marker. Welsh Income Tax rates for 2026/27 currently retain a £12,570 standard Personal Allowance.

The detailed meaning of the Welsh standard code is covered in the site’s C1257L tax code explanation.

What Should Employers Do When an Employee Is on Emergency Tax?

Employers should first collect the employee’s P45 where available. If there is no P45, HMRC’s starter checklist should be used to obtain the information needed for the first payroll submission.

The new starter must then be reported through an FPS on or before payday.

Where a P45 or starter checklist arrives late and HMRC has already issued a code, the employer should use the HMRC-issued code rather than replacing it with a code chosen independently.

HMRC can issue coding instructions to employers through notifications including P6 coding notices and annual P9 notices.

Where HMRC changes an employee’s code during the year, its employer guidance says payroll records should be updated as soon as possible.

Payroll teams should also remember that changing an employee from an emergency basis to cumulative treatment can create an automatic tax repayment through payroll.

The result should therefore be checked rather than assuming a large change in net pay is an error.

Can Emergency Tax Mean Someone Has Underpaid Tax?

Yes. Although emergency tax is frequently associated with overpayments, it can also result in insufficient tax being collected.

Because a non-cumulative code considers the current pay period rather than fully reconciling the year-to-date position, it may not immediately collect tax that should have been deducted earlier.

HMRC specifically states that if someone has not paid enough tax, they can remain on the emergency code until they have paid the correct amount for the tax year.

HMRC can subsequently adjust the code to collect an underpayment and can reconcile the final position after the tax year.

Frequently Asked Questions About Emergency Tax Codes

Is 1257L an emergency tax code?

No. 1257L alone is not an emergency tax code. It becomes emergency/non-cumulative when accompanied by W1, M1, X or NONCUM.

What is the emergency tax code for 2026/27?

HMRC’s standard emergency code is based on 1257L, reflecting the £12,570 Personal Allowance, and it is operated with a Week 1, Month 1 or other non-cumulative marker.

Is BR an emergency tax code?

Not by itself. BR means all income from that employment or pension is taxed at the basic rate. A separate W1, M1, X or NONCUM marker identifies emergency treatment.

Is 0T an emergency tax code?

0T alone is not automatically an emergency code. It means no Personal Allowance is being applied through that income source. 0T M1, for example, adds an emergency Month 1 marker.

How long can emergency tax last after starting a job?

HMRC says a new-job tax code update can take up to 35 days from the start of employment once it receives the required information from the relevant employers.

Can emergency tax last until April?

Yes. HMRC says an emergency code used after someone starts receiving company benefits or the State Pension can remain until the end of the tax year. A non-emergency code should then be used in the new tax year.

Can an employee change their tax code themselves?

An employee can correct information with HMRC, but they should not simply choose a different PAYE code for their employer to use. HMRC determines the tax code and sends the appropriate coding instruction to the employer or pension provider.

What should someone do if they have been emergency taxed for more than 35 days?

They should check their current tax code and employment information through HMRC’s online services and correct any inaccurate details. They should also confirm that their employer has received and applied any updated code.

Does emergency tax mean HMRC is investigating someone?

No. Emergency tax is an administrative PAYE method used when tax is being calculated on a non-cumulative basis. It is not a criminal penalty, fraud investigation or mechanism for freezing a bank account.

Can emergency tax be refunded?

Yes. If too much Income Tax has been deducted, a refund can often be made through payroll after HMRC corrects the code. If the overpayment remains after the end of the tax year, HMRC may deal with it through the PAYE reconciliation and P800 process.

Do taxpayers have to pay a company to claim an emergency tax refund?

No. HMRC says taxpayers can claim refunds themselves and do not need an agent. Commercial agents may charge fees for making claims on a customer’s behalf.