Registering for self assessment 25th September 2018 The deadline for registering for self assessment is 5 October for the 2017/18 tax year. Anyone submitting a self assessment return for the first time – including higher income child benefit charge (HICBC) taxpayers – need to register by 5th October 2018 so that they can complete and file their return by 31st January 2019 and avoid an automatic £100 penalty for failure to file. Individuals need to complete and file a tax return if they: earn more than £2,500 from renting out property; have a partner who receives child benefit and either has an annual income of more than £50,000, the so-called higher income child benefit charge; earned more than £2,500 in other untaxed income, for example from tips or commission; are self-employed sole traders; are limited company directors; are shareholders; employees claiming expenses in excess of £2,500 per tax year; or have an annual income over £100,000. The deadline for self assessment returns 2017-2018 is 31 January 2019.