You can change your tax code online through HMRC by checking and updating the employment, pension, income, benefits, and expenses information HMRC holds about you. If any information is incorrect or missing, HMRC can review your record and issue a new tax code where appropriate.
For the 2026/27 tax year, the standard Personal Allowance is £12,570 and the commonly used tax code for someone receiving the standard allowance is 1257L. Your actual tax code may differ because it reflects your individual circumstances.
How to Change Your Tax Code Online?
The quickest way to change your tax code online is to use HMRC’s Check your Income Tax service. You can check your current tax code, Personal Allowance, estimated income and employment details, then tell HMRC about information that is wrong or has changed.
Step 1: Sign in to Your HMRC Account
Sign in to your Personal Tax Account or the HMRC Check your Income Tax service. You may need to prove your identity before accessing your tax information.
Step 2: Check Your Current Tax Code
Look at the tax code shown in your HMRC record and compare it with the code on your latest payslip.
For example, if HMRC shows 1257L but your payslip shows a different code, investigate why the two records do not match.
Step 3: Review Your Income Details
Check the estimated income HMRC has recorded for each job or pension. Incorrect income information can result in too much or too little tax being deducted.
Step 4: Check Your Benefits and Expenses
Review taxable company benefits, employment expenses and other information that can affect your tax code. HMRC specifically allows you to update these details through its online service.
Step 5: Submit the Correct Information
Update anything that is wrong or missing and submit the information to HMRC. You are providing HMRC with the correct facts; HMRC determines whether your tax code needs to change.
Step 6: Check for the New Tax Code
If HMRC decides that your tax code needs to change, it will update the code and tell you and your employer or pension provider. HMRC says this should normally happen within 15 working days after you provide the required information.
How to Change Tax Code with HMRC?
If you want to know how to change tax code with HMRC, the important point is that you normally do not choose a new tax code yourself. Instead, you correct the information HMRC uses to calculate your code.
HMRC normally receives information from employers and pension providers, but you may need to notify HMRC of other changes yourself.
You may need to update HMRC when:
- You start or leave a job.
- You have more than one job.
- Your employment income changes.
- Your pension income changes.
- A company benefit starts or ends.
- Your estimated annual income is incorrect.
- You have employment expenses eligible for tax relief.
- You receive another taxable source of income.
Not every change will result in a new tax code. HMRC assesses the information and changes the code when necessary.
How Do I Change My Tax Code with HMRC?
If you are asking “how do I change my tax code with HMRC?”, you normally need to tell HMRC about the information that has changed rather than simply choosing a different tax code yourself.
Your tax code is calculated by HMRC. You can provide updated information, but you generally do not manually select the tax code that should apply.
Check Your Tax Code First
Before requesting a change, check your payslip or HMRC online account to see your current code.
For example, a tax code such as 1257L is commonly associated with the standard Personal Allowance for someone entitled to the full allowance, although individual circumstances can produce different codes.
Check Your Employment Details
Make sure HMRC has the correct employer listed and that your employment information is up to date.
If you have recently changed jobs, an old employment may still appear temporarily in your records.
Check Your Estimated Income
HMRC uses estimated income to calculate PAYE deductions. If your expected income has changed significantly, update the information held by HMRC.
Check Benefits and Other Income
Taxable benefits, pensions, and other income can affect your tax code. Make sure the information shown in your HMRC account is accurate.
Can I Change My Tax Code Online?
Yes, you can update the information that affects your tax code online. HMRC’s online Income Tax service allows you to check your tax code and Personal Allowance, update employment and pension details, report changes that affect your tax code, and see whether HMRC has changed your code.
However, there is an important distinction:
| Your action | HMRC action |
|---|---|
| Check your tax code | Explains how the code is calculated |
| Correct employment information | Reviews the updated information |
| Update estimated income | Recalculates your PAYE position |
| Report a company benefit | Considers whether the tax code should change |
| Claim eligible employment expenses | Considers the relevant tax relief |
| Report a change | Issues a new code if required |
This means you update your circumstances, rather than simply selecting a preferred tax code.
How to Change Your Tax Code on the HMRC App?
You can use the HMRC app to check your Income Tax information and update certain details that affect your PAYE record. HMRC’s guidance allows users to manage employment information, estimated income, and other relevant details through the app.
Check Your PAYE Information
Open the HMRC app and go to the Pay As You Earn (PAYE) section. Review the employment and income information shown in your account.
Update Incorrect Details
If an employer is missing, an old employment is still shown, or your estimated income is incorrect, update the relevant information.
Review Your Tax Code
After making changes, check your HMRC account or app for updates to your tax code.
Check Your Payslip
Once your employer receives a new code, compare it with the code shown on your next payslip. HMRC says a monthly-paid employee should normally see the new code on the next or following payslip after the new code is issued.
Important: The exact options available in the app can change as HMRC updates its digital services. If the required option is not available, use your HMRC online account or contact HMRC.
Can I Change My Tax Code on the HMRC App?
You may be able to update the information affecting your tax code through the HMRC app, depending on the type of change.
For example, if HMRC has incorrect information about your employment or estimated income, you may be able to report the change digitally.
However, if your situation is more complicated, you may need to contact HMRC directly.
Why Might You Need to Change Your Tax Code?
An incorrect tax code usually results from incorrect or missing information in HMRC’s records. Your tax code can change when your income or circumstances change.
Common reasons include:
Starting a New Job
When you start a new job, your employer sends information to HMRC. If HMRC does not yet have all the information it needs, you may initially receive an emergency tax code.
Having More Than One Job
You normally have only one Personal Allowance even if you have multiple jobs or pensions. HMRC may allocate different tax codes across your income sources.
Receiving a Pension
A new pension or a change in pension income can affect your tax code because the pension becomes part of your taxable income calculation.
Receiving Taxable Benefits
Benefits such as a company car or private medical insurance can affect your tax code because their taxable value may reduce the tax-free amount available through your code.
Your Estimated Income Changes
If HMRC’s estimate of your annual income is too high or too low, your PAYE deductions may not reflect your actual circumstances.
Claiming Employment Expenses
Certain employment expenses can qualify for tax relief. HMRC can take eligible relief into account when calculating your tax code.
How Do I Change My Tax Code with HMRC?
If you are asking “how do I change my tax code with HMRC?”, start by finding the information that is causing the problem.
For example, suppose your HMRC account shows that you still receive income from an old employer. The solution is not to select a different tax code. You should update the employment information so HMRC can recalculate your PAYE position.
Use this process:
- Check your current tax code.
- Compare it with your payslip.
- Review your employment and pension records.
- Check your estimated taxable income.
- Review taxable benefits and expenses.
- Correct missing or incorrect information.
- Submit the changes to HMRC.
- Check whether HMRC issues a new code.
If HMRC changes your code, it will normally send the new code to your employer or pension provider.
How to Get Your Tax Code Changed?
To get your tax code changed, you need to provide HMRC with accurate information about the circumstances affecting your PAYE calculation.
You may need to update:
- Employer details
- Employment income
- Pension income
- Estimated annual income
- Company benefits
- Employment expenses
- Other information affecting your Personal Allowance
Your employer or pension provider normally reports changes in employment and pension income. However, HMRC also expects individuals to report certain other changes, such as new income sources and taxable benefits.
What If I Have an Incorrect Tax Code?
If you have a wrong tax code, first check whether the code actually conflicts with your circumstances.
Your tax code is not simply a number showing your tax rate. The numbers and letters communicate information about your tax-free allowance and personal circumstances. For example, BR normally means all income from that job or pension is taxed at the basic rate.
Check Your Payslip
Find the tax code used by your employer on your latest payslip.
Check HMRC’s Record
Sign in to HMRC and compare the code with the one shown in your Income Tax record.
Check the Reason for the Code
HMRC normally provides an explanation when your tax code changes. Review the deductions and allowances included in the calculation.
Correct the Underlying Information
If the problem comes from an incorrect employer, income, pension or benefit record, update the relevant information rather than attempting to choose another code.
How to Check Whether Your Tax Code Is Correct?
Your tax code and your actual PAYE deduction are related but not identical checks.
HMRC recommends checking the tax code shown in your online account or app against your payslip. You can also use HMRC’s tax calculator to compare the tax that should be deducted with the amount shown on your payslip.
For example:
Payslip: 1257L
HMRC account: 1257L
If the codes match, check whether the PAYE deduction has been calculated correctly.
If the codes do not match, check whether your employer has received the latest HMRC code.
How to Ask HMRC to Change Your Tax Code?
If you need to ask HMRC to change your tax code, explain the specific information that is incorrect or has changed.
A useful explanation should identify:
- Your current tax code
- Your employer or pension provider
- The information you believe is incorrect
- The information that should replace it
- The date the change happened
- Any supporting information available
For example, if HMRC still lists an employment that ended several months ago, tell HMRC that the employment has ended and provide the relevant details.
The more specific the information, the easier it is to identify the issue.
How to Contact HMRC About a Tax Code Change?
If you cannot use the online service, you can contact HMRC about your Income Tax and PAYE position. HMRC provides an Income Tax enquiries service for questions about PAYE, tax codes and coding notices.
Before contacting HMRC, prepare:
- Your National Insurance number
- Current tax code
- Recent payslip
- Employer details
- Pension details, if relevant
- Estimated income
- Details of taxable benefits
- Information about any recent change
If you have recently started a new job, HMRC advises waiting 35 days for it to receive your new income details before contacting them about the new employment, unless there is another reason you need help.
What Happens After You Update Your Tax Code?
Updating your details does not guarantee that HMRC will issue a new code. Not every reported change affects your tax code.
If HMRC determines that a new code is required, it will:
- Update your tax code.
- Tell you about the change.
- Send the new code to your employer or pension provider.
- Allow your employer or pension provider to use the new code for PAYE.
HMRC says a new tax code should normally reach you and your employer within 15 working days after you provide the necessary information.
When Will the New Tax Code Appear on My Payslip?
The timing depends on your pay frequency.
According to HMRC, after it issues a new tax code:
- Monthly pay: the new code should normally appear on your next or following payslip.
- Weekly pay: the new code should normally appear on your third payslip.
If your payslip still shows the old code after HMRC has issued a new one, speak to your employer and ask whether its payroll records have been updated.
Can a Tax Code Change Give Me a Tax Refund?
Yes, an incorrect tax code can result in too much tax being deducted. If HMRC corrects the code and you have overpaid tax, the correction can result in a refund or adjustment through PAYE, depending on your circumstances.
The opposite can also happen. If too little tax was deducted because of an incorrect code, you may have tax to pay.
The important step is to correct the underlying information rather than changing the code simply to reduce your current deduction.
Common Tax Codes You May See
Your tax code contains both numbers and letters. The numbers generally relate to the amount of tax-free income allocated through the code, while the letters reflect your circumstances.
| Tax code | General meaning |
|---|---|
| 1257L | Common code for someone receiving the standard Personal Allowance |
| BR | Income from that job or pension is normally taxed at the basic rate |
| D0 | Income from that job or pension is normally taxed at the higher rate |
| D1 | Income from that job or pension is normally taxed at the additional rate |
| 0T | No Personal Allowance is included in the code |
| K code | Taxable deductions exceed the tax-free allowances included in the code |
The exact meaning depends on your circumstances. HMRC’s tax code checker can explain the specific code on your payslip.
What Is an Emergency Tax Code?
An emergency tax code may be used when HMRC does not yet have all the information required to calculate your normal code.
You may see an emergency suffix such as:
- W1 for weekly pay
- M1 for monthly pay
- X where pay dates vary
- NONCUM on some payslips
For example, you could see 1257L W1 or another code with an emergency suffix.
Emergency taxation often occurs after starting a new job. It does not necessarily mean that HMRC has permanently assigned the wrong tax code.
What If You Have More Than One Job?
If you have more than one job, you normally receive one Personal Allowance across your income, rather than a separate full allowance for every job.
HMRC may therefore use different tax codes for different employments. For example, one job could use 1257L, while another could use BR.
If the allocation does not reflect your circumstances, check your PAYE records and update HMRC.
Frequently Asked Questions
How do I change my tax code online?
Sign in to HMRC Check your Income Tax service, review your employment, pension, estimated income, benefits and expenses information, and update anything that is wrong or missing. HMRC will decide whether your tax code needs to change.
How do I change my tax code with HMRC?
You normally change the information that affects your tax code rather than choosing a new code yourself. HMRC reviews the updated information and issues a new code if appropriate.
Can I change my tax code online?
Yes. HMRC allows you to check and update information affecting your PAYE tax code through its online Income Tax service.
How do I change my tax code on the HMRC app?
Sign in to the HMRC app, go to the PAYE section, review your employment and income information, and update details that are incorrect or missing.
Can I change my tax code on the HMRC app?
You can update relevant information through the HMRC app, but you do not normally select the replacement tax code yourself. HMRC determines the appropriate code after reviewing your circumstances.
How can I get my tax code changed?
Correct the information HMRC holds about your employment, income, pension, benefits or expenses. If HMRC determines that the code needs changing, it will issue the revised code to you and your employer or pension provider.
What should I do if I have an incorrect tax code?
Compare the tax code on your payslip with the code in your HMRC account. Then check the employment, income, pension and benefit information used to calculate it. Correct any inaccurate information through HMRC’s online service.
How do I ask HMRC to change my tax code?
Tell HMRC which information is incorrect or has changed. Include the relevant employment, income, pension or benefit details. If you cannot use the online service, contact HMRC Income Tax service.
How long does HMRC take to change a tax code?
HMRC says it will normally update your tax code and tell you and your employer within 15 working days if a change is required after you provide the necessary information.
When will my new tax code appear on my payslip?
If you are paid monthly, HMRC says the new code should normally appear on your next or following payslip. If you are paid weekly, it should normally appear on your third payslip.
Can an incorrect tax code cause me to overpay tax?
Yes. If your tax code does not reflect your circumstances, you may pay too much or too little PAYE tax. Correcting the underlying information can allow HMRC to adjust your tax code and correct the position.
Does HMRC automatically change tax codes?
HMRC can change your tax code when it receives updated information about your income or circumstances. Examples include starting a job, receiving taxable benefits, changes to pension income, claiming Marriage Allowance, or changes to tax relief.
What if my tax code and payslip do not match?
Check your HMRC account to see whether HMRC has issued a newer code. If HMRC has issued a new code but your payslip still shows the old one, contact your employer to check its payroll records.
Do I need to contact HMRC if I start a new job?
Your employer normally tells HMRC when you start a new job. If your details are missing or incorrect, you can update them online. HMRC advises waiting 35 days for new employment income details to arrive before contacting them about the new job if there is no other urgent issue.
What is the most common tax code in the UK?
1257L is currently the tax code used for most people with one job or pension who receive the standard Personal Allowance. Individual tax codes can differ because they reflect personal circumstances.
What is the tax code for 2026/27?
The standard Personal Allowance for 2026/27 is £12,570, and the emergency code is 1257L. Your individual tax code may be different depending on your income and circumstances.
Can HMRC change my tax code if I have taxable benefits?
Yes. Taxable benefits such as a company car or medical insurance can affect the calculation of your tax code. You should check that HMRC’s benefit information is accurate.
Can I change my tax code myself?
You can update the information used to calculate your tax code, but HMRC determines the actual code. This distinction prevents you from selecting a code that does not reflect your tax position.
What should I do if I still think my tax code is wrong?
Review your HMRC Income Tax record, compare it with your payslip and correct any missing or inaccurate information. If the issue remains or you cannot use HMRC’s online service, contact HMRC for assistance.