Understand your Simple Assessment tax bill
If the amounts used in your tax calculation are wrong
Call or write to HMRC within 60 days of the date on your tax bill if you think the amounts in the calculation are wrong.
You’ll need to tell HMRC:
- which amounts you think are wrong
- what the amounts should be
You should explain what records you used to check your tax calculation. This could include documents such as payslips, bank statements or pension information.
HMRC may ask you to send these records as evidence.
What happens next
If HMRC agrees that your Simple Assessment was wrong, you’ll be sent a new Simple Assessment with an updated tax calculation.
If they disagree, you’ll get a decision letter explaining why, how to pay and how to appeal if you still disagree.
You’ll still need to pay your Simple Assessment tax bill by the deadline unless HMRC tells you they’ll delay your payment date.
How to appeal
If you disagree with HMRC’s decision in the letter, you can make an appeal. Your letter will tell you how to do this.
You have 30 days from the date your decision letter was issued to appeal.