Held, appeal and claim for judicial review allowed. The extended definition of “person” in section 26 of the Competition Act 1998 meant that a section 26 notice could be “served” on an undertaking, although since an undertaking was an economic entity without the attributes of legal persons like companies which enabled service, in order to be effective the notice had to be brought to the attention of a natural or legal person. Where a notice clearly addressed to an undertaking as a whole was served on a component entity with a UK territorial connection, that entity was obliged to provide the Competition and Markets Authority the documents and information responsive to the notice in its own control, including those documents held abroad and via controlled subsidiaries. Additionally, because the notice was addressed to the undertaking, the entity had to notify other entities within the undertaking who, providing they had a a UK territorial connection, were required to respond as if the notice were directed to them specifically. However, the imposition of an obligation on an entity operating solely in a foreign jurisdiction to provide an administrative authority in another jurisdiction (under threat of sanction) with documents and information was plainly extraterritorial and very likely to undermine comity between nations. Construing section 26 in accordance with the presumption against extraterritorial effect, the Competition and Markets Authority could not compel a constituent element of an undertaking, that was not subject to the territorial jurisdiction of the United Kingdom, to respond to a section 26 notice. Accordingly, no notice, whether sent directly or indirectly to the German parent companies, was effective (paras 71–77, 73, 78–80).