ICOCA can be also used in the section between Kita-senju Station and Ayase Station on the Chiyoda Line of Tokyo Metro Co., Ltd., since it's considered a part of the (JR) Joban Kankosen (Joban local line).
なお、東京地下鉄千代田線の北千住～綾瀬間は常磐緩行線の一部としてICOCAが利用できる。