This is the third edition of the impact assessment that was first published on 4 December 2018. This edition includes the impacts of the customs, VAT and excise regulations laid before Parliament in February, March and September 2019 (under the Taxation (Cross-border Trade) Act 2018 (TCTA 2018) and the EU Withdrawal Act 2018 (EUWA 2018)) and adds to the impacts that were published on 25 February 2019.
Source HMRC