As a result of the agreement between the UK and EU last 24th December 2020, the UK is no longer part of the EU’s single market and customs union and new rules apply.
From 1st January, the UK has extended the rules which applied to non-EU postal items before. Similarly, the EU now treats postal items from the UK as it did non-EU items before. This means there may be changes to how you send and receive items from abroad.
You can find more information here