Regulation 4 sets out the circumstances in which carbon units are to be credited to and debited  from the net UK carbon account to take into account domestic aviation emissions during 2018. It  relies on the calculation of a domestic aviation cap in accordance with the Schedule.  Regulation 5 of these Regulations places a duty on the Secretary of State to cancel all the carbon  units (if any) credited to the net UK carbon account in respect of 2018 following their acquisition  by the Secretary of State.  Regulation 6 amends the Carbon Accounting Regulations 2009 in two respects. First, it updates  the definition of European Union allowance. Second, it amends the duty in regulation 9 of the  2009 Regulations on the Secretary of State to keep a register of carbon units credited to and  debited from the net UK carbon account so that it takes account of these Regulations.  An impact assessment has not been produced for this instrument as no impact on the private or  voluntary sectors is foreseen.  £4.90  UK202002041006 02/2020 19585  http://www.legislation.gov.uk/id/uksi/2020/115  © Crown copyright 2020  Printed and published in the UK by The Stationery Office Limited under the authority and superintendence of Jeff James,  Controller of Her Majesty’s Stationery Office and Queen’s Printer of Acts of Parliament.  ISBN 978-0-11-119289-4