2. Income changes

You must tell HM Revenue and Customs (HMRC) about changes to your taxable income.

To do this you can either:

If you don’t, you could pay too much tax or get a tax bill at the end of the year.

What you must tell HMRC

Your employer or pension provider tells HMRC when:

  • you start or finish your job
  • there’s a change in the money you earn from your job or get from your pension

But you must tell HMRC about any other changes, eg when you start or stop getting:

If you get tax credits

Tell HMRC separately about changes that affect your tax credits.

If your spouse or civil partner dies

Tell HMRC about changes to your income after the death of your husband, wife or civil partner.

If you make Self Assessment ‘payments on account’

Tell HMRC if you expect a big decrease in income and you pay your Self Assessment tax bill in advance (‘payments on account’). HMRC may decide to reduce your payments.

After you tell HMRC

HMRC may:

  • change your tax code and send you a PAYE Coding notice
  • tell you to send a Self Assessment tax return so they can bill you for tax you owe
  • send you a refund if you paid too much tax