Tax codes
How to update your tax code
In most cases, HMRC will automatically update your tax code when your income changes. They’ll 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’re 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’re contacting HMRC on someone else’s behalf
If you need to tell HMRC about a change in someone else’s income (for example, because you’re their accountant) fill in a PAYE Coding Notice query form.
Get a tax refund or pay the tax you owe
If you’ve paid too much or too little tax at the end of the tax year HMRC will send you either:
-
a tax calculation letter (known as a ‘P800’)