Emergency Tax Codes Explained

What Is an Emergency Tax Code?

An emergency tax code is a temporary or non-cumulative tax code used when your employer or HMRC does not have enough up-to-date information to calculate your Income Tax in the normal cumulative way.

Under a normal cumulative code, payroll generally considers your taxable pay and tax deductions from earlier in the tax year.

Under an emergency code, tax is normally calculated by looking only at the pay and allowance available for the current week or month.

This means you are effectively taxed as though the amount earned in that pay period will continue at the same rate throughout the year.

What Are the Most Common Emergency Tax Codes?

HMRC states that you are normally on an emergency tax code where the code ends in:

• W1 – generally used for employees paid weekly
• M1 – generally used for employees paid monthly
• X – commonly used where pay dates vary
• NONCUM – another payroll description for a non-cumulative code

Examples may include:

• 1257L W1
• 1257L M1
• 1257L X
• S1257L M1 for a Scottish taxpayer
• C1257L X for a Welsh taxpayer

Tax codes and Personal Allowance amounts can change between tax years. You should check the code against the tax year shown on your payslip rather than relying on an example from an older article.

Why Have I Been Placed on an Emergency Tax Code?

Emergency tax codes are commonly used where HMRC or payroll does not yet have complete information about your income and tax already paid.

This can happen if:

• You have started a new job
• Your new employer has not received your P45
• You did not complete a starter checklist correctly
• You started your first job in the UK
• You returned to employment after a career break
• You started work after a period of self-employment
• You returned from working overseas
• You have more than one job
• You started receiving a pension
• You began receiving company benefits or the State Pension
• HMRC has outdated employment information
• Your previous employment is still shown as active

The code is used so that your employer can pay you while the correct payroll and tax information is being established.

How Do I Know If I Am on an Emergency Tax Code?

Your tax code should normally appear on your payslip.

You may also find it on:

• Your P60
• Your P45
• A tax-code notice from HMRC
• Your HMRC Personal Tax Account
• The HMRC app
• A pension statement or pension-provider document

Look for W1, M1, X or NONCUM at the end of or alongside the code.

You should also compare the tax code shown on your payslip with the latest code HMRC has issued for that employment.

Where the codes differ, your employer may not yet have received or applied HMRC's updated instruction.

Does an Emergency Tax Code Mean I Will Pay More Tax?

It can result in too much tax being deducted, particularly where your earlier pay, unused Personal Allowance or tax already paid has not been taken into account.

For example, you may overpay where:

• You start a new job after a period without income
• You have unused Personal Allowance from earlier in the year
• Your employer does not receive your previous pay and tax details
• Your previous employment is incorrectly treated as continuing
• Your tax-free allowance is allocated to the wrong employment

However, an emergency code can also result in too little tax being deducted. This is why you should not assume that every emergency code will produce a refund.

The correct position can only be established after your total income, tax already deducted and available allowances are reviewed.

What Should I Do If I Am on an Emergency Tax Code?

Start by checking whether your employer and HMRC have the information required to calculate the correct code.

You should:

• Check the code shown on your latest payslip
• Review your tax code through your HMRC online account
• Give your P45 to your new employer where available
• Ask your former employer for a P45 if one was not provided
• Complete a starter checklist if you do not have a P45
• Check that old employments have been marked as ended
• Confirm whether you have another job or pension
• Update incorrect employment details with HMRC

How to Correct an Emergency Tax Code in 7 Steps

1. Check your payslip. Confirm the exact tax code being used and whether it ends in W1, M1, X or NONCUM.
2. Check your HMRC record. Sign in to your Personal Tax Account or the HMRC app and review the employments, pensions, income estimates and tax codes shown.
3. Find your P45. Give your new employer the P45 from your previous job where you have one.
4. Correct missing starter information. If you have not yet been paid and do not have a P45, complete the starter checklist accurately and give it to your employer.
5. Update incorrect employment details. Tell HMRC if a previous employment has ended, an income estimate is wrong or an employment is missing.
6. Wait for the corrected code to reach payroll. HMRC will issue the updated code to you and your employer where a change is required.
7. Check the next payslips. Confirm that the new code has been applied and review whether any overpaid tax has been refunded through your wages.

How Long Does It Take to Fix an Emergency Tax Code?

The timeframe depends on how quickly HMRC receives accurate information from you, your former employer, your new employer and any pension provider involved.

HMRC currently states that where you have started a new job, it will usually update your tax code after receiving the required information from your new and previous employers.

This can take up to 35 days from the date you start the job.

When HMRC sends an updated code to your employer, it should normally be applied through a later payroll run.

Where you are paid monthly, HMRC says the corrected code and payroll refund may appear in your next or following pay. For weekly payroll, it may appear by your third pay after the employer receives the code.

Processing may take longer where:

• An employer has not submitted the necessary payroll information
• Your previous employment is still recorded as active
• You have several jobs or pensions
• HMRC needs clarification about your income
• Your identity or employment information requires checking

Can I Claim Back Tax Overpaid Through an Emergency Code?

Yes. If an emergency code caused too much Income Tax to be deducted, you may be entitled to recover the overpayment.

The repayment method depends on when the overpayment occurred.

Overpayment during the current tax year

If HMRC corrects your tax code during the same tax year and has all the required income information, the refund may be made automatically through your wages or pension.

Your employer or pension provider will normally apply the corrected code and refund the difference through payroll where appropriate.

Overpayment after leaving a job

If you have stopped working and do not expect to start another job immediately, a different HMRC repayment process may apply.

HMRC will need details of your income, tax already paid and current employment position before calculating whether a repayment is due.

Overpayment from a previous tax year

After a tax year ends, HMRC normally reviews the income and tax information supplied by employers and pension providers.

HMRC may issue a P800 tax calculation explaining whether you paid too much or too little tax and how to obtain any refund.

Where HMRC has not automatically corrected the overpayment, you may need to make a repayment claim.

Learn more through our PAYE Tax Refund service .

Will HMRC Automatically Refund Me?

Sometimes. If HMRC corrects your code during the current year and has complete income information, the overpayment can often be refunded through payroll.

After the tax year ends, HMRC may reconcile your PAYE records and send a P800 calculation if you paid the wrong amount.

However, you should not assume that every overpayment will be corrected immediately or without action.

You may need to follow up where:

• Your employment record is incomplete
• Your former employer has not reported final pay correctly
• Your address or contact details are outdated
• The wrong employment remains active
• You have not claimed a refund shown on a P800
• The overpayment relates to an earlier tax year

Our guide to how far back you can claim a tax refund explains the time limits that may apply to earlier years.

What Happens If I Do Nothing?

The emergency code may be corrected automatically once HMRC receives complete information, but relying on this can allow an error to remain unresolved for longer than necessary.

Possible consequences include:

• Continuing to pay too much tax
• Paying too little tax and owing HMRC later
• Receiving a smaller take-home wage
• Having your Personal Allowance allocated incorrectly
• Waiting until after the tax year for a reconciliation
• Missing correspondence sent by HMRC

HMRC states that some emergency codes connected with company benefits or State Pension may remain until the end of the tax year before being replaced with a non-emergency code.

You should therefore check the reason for the code rather than assuming that it will always disappear after the next payday.

Common Situations That Lead to Emergency Tax Codes

Starting a new job

If your new employer does not have your previous income and tax details, it may use an emergency code for your first payment.

Changing employers

A delay in receiving or applying your P45 can cause payroll to use an emergency code.

The amount you earn in the new job does not itself determine whether an emergency code is used.

Returning to work

You may be asked to complete a starter checklist after returning from a break in employment, self-employment or overseas work.

Having more than one job

HMRC must decide how your Personal Allowance and tax bands should be allocated between your employments.

Incorrect or incomplete information can cause the wrong code to be applied to one or both jobs.

Starting a pension

A pension provider may initially use an emergency code while HMRC establishes your other income and allowances.

Receiving company benefits or State Pension

HMRC may temporarily use an emergency code while updating your taxable benefits or State Pension income.

How Can I Reduce the Risk of Emergency Tax?

You cannot prevent every temporary payroll issue, but you can reduce the risk by keeping your employment information accurate.

You should:

• Give your P45 to your new employer promptly
• Complete the starter checklist accurately where required
• Use your correct National Insurance number
• Check the first payslip from every new job
• Review your HMRC Personal Tax Account
• Confirm that old employments have been closed
• Check estimated income figures held by HMRC
• Tell HMRC about changes to jobs, pensions and company benefits
• Review every tax-code notice you receive

It is particularly important to check your code when you start or leave a job, take on additional employment or begin receiving a pension.

Other Tax Codes You May See

Not every unfamiliar tax code is an emergency code.

Other common codes include:

• 1257L: A common standard code for many taxpayers in England and Northern Ireland, subject to the applicable tax year and individual circumstances
• BR: All income from that source is taxed at the basic rate
• D0: All income from that source is taxed at the higher rate
• D1: All income from that source is taxed at the additional rate
• 0T: No Personal Allowance is applied to that source
• NT: No Income Tax is deducted from that source
• K code: Adjustments exceed the available tax-free allowance

Scottish and Welsh taxpayers may also see an S or C prefix.

What Information Should I Have Before Contacting HMRC?

Having the right records available can make it easier to identify and correct the problem.

Useful information includes:

• Your National Insurance number
• Your current tax code
• Your employer's name and PAYE reference
• Your employment start date
• Your P45
• Your latest payslips
• Your previous employer's details
• Your expected annual income
• Details of other jobs or pensions
• Any relevant HMRC tax-code notices

Check that the information you provide matches the records held by your employer wherever possible.

How Long Will an Emergency Tax Refund Take?

There is no single processing time for every emergency tax refund.

A current-year overpayment may be corrected through payroll after HMRC sends the updated code to your employer.

A previous-year repayment may require HMRC to complete a PAYE reconciliation or issue a P800 before payment can be claimed.

The timeframe can depend on:

• Whether HMRC has complete income information
• Whether the employer has received the corrected code
• Your payroll frequency
• Whether the tax year has ended
• Whether HMRC needs additional evidence
• The method used to issue the repayment

Read our guide to HMRC tax refund times for more information.

Frequently Asked Questions

Is an emergency tax code permanent?

Emergency codes are intended to be temporary or to operate until HMRC has enough information to calculate your tax correctly.

However, the length of time for which the code applies depends on why it was issued and whether the necessary information has been supplied.

Is 1257L an emergency tax code?

Not by itself. A code such as 1257L normally becomes an emergency code when it includes W1, M1, X or NONCUM.

Can I still be paid while on an emergency tax code?

Yes. The emergency code allows your employer to calculate a tax deduction and pay your wages while the correct information is being established.

Will HMRC automatically refund me?

It may refund a current-year overpayment through payroll after issuing a corrected code.

In other situations, particularly after the tax year has ended, HMRC may issue a calculation or require you to claim the repayment.

How do I know whether my code has been updated?

Check your latest payslip, HMRC Personal Tax Account and any tax-code notice sent by HMRC.

Your payslip should eventually show the corrected code after your employer receives and applies it.

Should I ask my employer to choose a different tax code?

Employers must normally use the tax code and payroll information supplied through the appropriate HMRC process.

Payroll cannot simply select whichever code produces the preferred take-home pay.

Can an emergency code mean I owe tax?

Yes. Emergency codes can result in too little as well as too much tax being deducted.

HMRC may adjust a later tax code or issue a calculation if additional tax is due.

Can I claim for an emergency-tax overpayment from an earlier year?

Potentially, yes, provided the year remains within the applicable repayment time limit and HMRC's records support the overpayment.