At the end of the transition period, the eCommerce Directive will no longer apply to the UK. Updated guidance on why the eCommerce Directive will no longer apply after the transition period and what you should do to prepare, can be found here, The eCommerce Directive after the transition period.
The eCommerce Directive regulates online activities such as online information, advertising, shopping and contracting. The Directive allows operators to operate in any European Economic Area (EEA) country, according to the regulations that apply in the country in which they are established.
After the UK leaves the EU on the 1st of January, 2021, these rules will no longer apply and operators will have to comply with the rules of each EEA country that they operate in; EEA operators in the UK will have to comply with UK regulations.
Companies are advised to check how this may affect their online activities and take legal advice as required.