HM Treasury and Department of International Trade announcement 21st November. The Bill will allow the UK to set and collect its own duty on goods coming into the country and will allow the government to implement different outcomes of the EU negotiations, including an implementation period.
https://www.gov.uk/government/news/taxation-cross-border-trade-bill-introduced-in-parliament
Explanatory Notes, Impact Assessment etc at
https://www.gov.uk/government/publications/taxation-cross-border-trade-bill