The United Kingdom (UK) left the European Union (EU) on January 31, 2020, and is now in a transition period with the EU until at least December 31, 2020.
Global Affairs Canada has confirmed that during the transition period the UK will remain a party to the Comprehensive Economic Trade Agreement (CETA). CBSA has also confirmed that there is no impact on UK originating goods as a beneficiary of the CEUT treatment. As there is no change to trade during this transition period CBSA will not be issuing any customs notices.
Further information is available at https://www.tradecommissioner.gc.ca/united-kingdom-royaume-uni/information-brexit-renseignements.aspx?lang=eng