This Order sets a limit of the net amount of carbon units that may be credited to the net UK carbon account for the 2018-2022 budgetary period of 55,000,000 carbon units. Article 3(2) sets out certain carbon units which are excluded from the level of the limit. They are carbon units credited to and debited from the net UK carbon account as a result of the operation of the EU emissions trading scheme during the 2018-2022 budgetary period in accordance with regulations made under section 27(3) of the Climate Change Act 2008. Carbon units are defined in regulation 3 of the Carbon Accounting Regulations 2009 (S.I. 2009/1257).