How to Correct a Wrong PAYE Tax Code With HMRC and Update Your Income Details

First check whether HMRC or your employer has the wrong tax code

Your PAYE tax code tells an employer or pension provider how much Income Tax to deduct. HMRC normally calculates the code using information supplied by employers and pension providers together with information about your allowances, other income, benefits and deductions.

Start by checking the tax code HMRC currently holds for you in the Check your Income Tax service or HMRC app. Compare it with the code printed on your payslip. If the code in HMRC's records and the code used on your payslip are different, contact your employer because payroll may not yet be using the code HMRC issued.

If the two codes match but the code does not reflect your actual circumstances, review the information HMRC used to calculate it.

Check the income and employment details HMRC has for you

HMRC says a wrong tax code is usually caused by incorrect or missing information. In the online service, check:

• all current employers;
• whether an old employment is still recorded as active;
• your estimated taxable income from each job;
• pension income;
• company benefits, such as a company car or medical insurance;
• employment expenses or tax relief that may affect your code.

If you have more than one job, HMRC gives you a tax code for each employment. Its guidance for new or multiple jobs also recommends checking that HMRC has all your current employers and that your estimated annual income is realistic.

Correct your PAYE details through HMRC online services

The online service is HMRC's quickest route for checking and updating the information behind your tax code. Sign in to Check your Income Tax for the current year, review your PAYE record and change any details that are wrong or missing.

You can use HMRC online services or the HMRC app to update an employer, add a missing employer, report that a job has ended and update your estimated annual income. HMRC also provides routes for reporting changes to employment income, pension income and company benefits.

If employment expenses are missing from your tax position, check whether you qualify to claim tax relief for work expenses you paid yourself.

Wrong tax code after changing jobs

If you have started a new job, your employer sends HMRC your employment and income information. If the necessary previous income information is not available in time, you can initially be put on a temporary emergency tax code.

If you have a P45 from your previous job, give it to your new employer. If your former employer did not provide one, ask them for it. Where a new starter does not have a P45 before their first pay, the employer can use the official starter checklist to obtain the information needed to select an initial code.

HMRC says that if you have already received your first pay, you should not use the starter checklist to correct the tax code; instead, use the Check your Income Tax service to review and update your information.

For a newly started job, HMRC advises waiting 35 days from starting the job before contacting HMRC because it may still be receiving the necessary income details from your employers. HMRC's separate guidance says new employment details can take up to around six weeks after the first payday to become visible online.

Check whether you are on an emergency tax code

HMRC identifies emergency tax codes by endings such as W1, M1 or X; some payroll systems may show NONCUM. Under an emergency code, tax is calculated using the current pay period rather than your total income so far for the tax year, so you can temporarily pay too much or too little.

If you started a new job and your employer did not have your earlier pay and tax information, an emergency code is usually temporary. HMRC says it normally updates the code when it receives all the relevant information.

What happens after you update your details

Changing information does not automatically mean your tax code will change. HMRC first considers whether the corrected information affects the calculation.

If a new code is required, HMRC says it will update the tax code and tell you and your employer or pension provider within 15 working days.

After the new code has been issued, it should normally appear:

• on the next or following payslip if you are paid monthly;
• on the third payslip if you are paid weekly.

If the new code does not appear, ask your employer to check whether HMRC's updated code has reached payroll.

If you paid the wrong amount of Income Tax

A wrong code can result in too much or too little Income Tax being deducted. When HMRC changes a code and has the necessary income information, it checks the tax already paid against the amount that should have been paid.

If you paid too much through your job or pension, HMRC can normally instruct the employer or pension provider to refund the difference through your pay when the new tax code is used. For other Income Tax overpayments and situations where a separate claim is appropriate, see how to claim an Income Tax refund from HMRC.

If you have paid too little, HMRC may estimate the amount owed and, where possible, adjust your tax code so the tax is collected over one or more tax years. HMRC also checks PAYE records after the end of the tax year and may contact you if the final amount paid was not correct.

Avoid these common PAYE tax-code problems

• Do not assume the code itself is the only problem. First compare HMRC's recorded code with the one used by your employer.
• Do not leave an old job showing as current. Tell HMRC when an employment has ended if its records are wrong.
• Do not ignore an unrealistic income estimate. Update HMRC's estimated annual income if it does not reflect what you expect to earn.
• Check every employment separately. If you have several jobs, you normally have a tax code for each one.
• Do not contact HMRC immediately after starting a job solely because the initial code looks temporary. HMRC advises waiting 35 days before contacting it about a wrong code after starting a new job.

If you cannot use HMRC's online service

If you cannot use or create a personal tax account, HMRC provides Income Tax contact routes for help with PAYE and tax-code enquiries. The online service remains the quickest official route where you can use it.

When reviewing your account, also make sure HMRC has your current contact information. If you have moved, you can follow the separate Helpydo guide on how to tell HMRC your new home address.