New import procedures from the EU
The following link highlights that from 1st January there will be new import procedures for EU goods, which are moving away from the current simplified procedures for imports, to the full procures (as per non-EU countries). In most cases, companies’ customs agents will do the paperwork, but they’ll need more info and will charge more. There’s concerns that there may also be delays at ports in the first few days / weeks of new year, as insufficient import declarations hold up goods.
https://www.gov.uk/government/publications/guides-to-importing-and-exporting-goods-between-great-britain-and-the-eu