Tax codes

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How to update your tax code

In most cases, HMRC will automatically update your tax code when your income changes. They鈥檒l usually get this information from your employer.

If HMRC has the wrong information about your income, you may be given an incorrect tax code.

To correct your tax code, make sure HMRC has up-to-date details about your income.

Check what you need to do if you鈥檙e on an emergency tax code.

If you think your tax code is wrong

If you think your tax code is wrong, you can use the Check your Income Tax online service to:

  • update your employment details
  • tell HMRC about a change in income that may have affected your tax code

For example, you can:

  • add company benefits
  • add missing employers or income
  • claim employment expenses
  • update your estimated taxable income

HMRC may change your tax code as a result of the updates you make in the online service.

If you cannot use the online service

If you think your tax code is wrong and you cannot use the online service, you can contact HMRC.

After you update your details

HMRC will tell you if they change your tax code.

They will also tell your employer or pension provider that your tax code has changed.

Your next payslip should show:

  • your new tax code

  • adjustments to your pay if you were paying the wrong amount of tax

If you鈥檙e contacting HMRC on someone else鈥檚 behalf

If you need to tell HMRC about a change in someone else鈥檚 income (for example, because you鈥檙e their accountant) fill in a .

Get a tax refund or pay the tax you owe

If you鈥檝e paid too much or too little tax at the end of the tax year HMRC will send you either:

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