6. If you think your code is wrong

You may think your tax code is wrong if, for example:

Emergency tax codes are usually updated automatically after you’ve given your new employer your P45.

To report a mistake you can:

If HMRC agrees your tax code is wrong, they’ll adjust it so that you:

  • pay the right amount of tax for all of your income, spread over a year
  • get the Personal Allowance you’re entitled to

At the end of the tax year

You can check you paid the right amount of tax after the end of the tax year (5 April).

You can claim a refund if you think you’ve paid too much.