Recommendation 24

If Parliament is to be able to effectively scrutinise the environmental impact of tax changes it needs good quality information. For each tax policy change, the exchequer departments publish a Tax Information and Impact Note (TIIN) explaining the objective of the change, and its revenue and other impacts. The NAO found that for tax changes with an environmental objective, TIINs described but rarely quantified environmental impacts.48 We asked the exchequer departments why they did not require the expected environmental impacts of tax measures to be quantified in TIINs. HM Treasury told us that decisions on what analysis to publish were for ministers. However, HMRC told us its analysts quantify impacts whenever they can, and that work depended on analysts having 40 C&AG’s Report, para 1.6 41 Q 87 42 Q 45; The Dasgupta Review, The Economics of Biodiversity: Headline Messages, February 2021, page 2 43 Qq 50, 82: C&AG’s Report, para 2.5 44 Q 1 45 Office of Budget Responsibility, Economic and Fiscal Outlook, CP 387, March 2021, paras 1.34, 3.11 46 HM Treasury, Budget 2021: policy costings, March 2021, page 18 47 Qq 1, 4 48 C&AG’s Report, paras 1.15–1.16 14 Environmental tax measures models and methods to do this. It said that progress was being made in quantifying impacts, citing the quantification of expected carbon reductions from the new plastic packaging tax, but it also recognised that it had more to do.49 Monitoring and evaluating tax measures