If a product is not registered in GB but serialised packs are shipped/exported to GB, is it allowed to ship the serialised packs from 2023 onwards? Is there any requirement to be considered for the non-registered products?

Any “serialised” pack sent to the new GB market, regardless of the licence type, should be accompanied by the data that belongs to it. If a manufacturer wishes not to load the data for packs they send exclusively for the GB market use, the serialisation of the packs should not be applied.