The deadline for submitting your 2017/18 self assessment return is 31 January 2019. The deadline applies to taxpayers who need to complete a tax return and make direct payments to HMRC in respect of their income tax, Classes 2 and 4 National Insurance Contributions (NIC), capital gains tax and High Income Child Benefit Charge liabilities.
There is a penalty of £100 if a taxpayer’s return is not submitted on time, even if there is no tax due or the return shows that they are due a tax refund.
The balance of any outstanding income tax, Classes 2 and 4 NIC, capital gains tax and High Income Child Benefit Charge for the year ended 5th April 2018 is also due for payment by 31 January 2019. Where the payment is made late interest will be charged.
The first payment on account for 2018/19 in respect of income tax and any Class 4 NIC or High Income Child Benefit Charge is also due for payment by 31st January 2019.