Deadline for paper submission of self-assessment tax return for tax year ended 5 April 2018. New fuel rates come into force. Deadline for online submission of self-assessment tax returns for tax year ended 5 April 2018 for HMRC to collect tax through PAYE codes, where they owe less than £3,000. Residence nil-rate band increases from £125,000 to £150,000. Residence nil-rate band increases from £150,000 to £175,000.