Customs and Tariff Bureau expresses its position on the effectiveness of the Agreement concerned with UK leaving EU, and says the beneficial tariff will be effective at least until Dec.30, 2020 in two ways when EU and UK agree to set transition period.
If the transition period is not arranged by the two parties, WTO tariff is applied to the goods traded between UK and Japan.
http://www.customs.go.jp/kyotsu/kokusai/news/brexit-tariff-announcement.htm
