1. The national enforcement bodies shall closely monitor compliance with this Regulation, including with Regulations (EU) No 454/2011 and (EU) No 1300/2014 as far as those Regulations are referred to in this Regulation, and shall take the measures necessary to ensure that the rights of passengers are upheld.
2. For the purpose of paragraph 1, railway undertakings, station managers, infrastructure managers, ticket vendors and tour operators shall provide the national enforcement bodies with relevant documents and information at their request without undue delay and, in any event, within one month from the receipt of the request. In complex cases, the national enforcement body may extend this period to a maximum of three months from the receipt of the request. In carrying out their functions, the national enforcement bodies shall take account of the information submitted to them by the body designated under Article 33 to handle complaints, if this is a different body. They may also decide on enforcement actions based on individual complaints transmitted by such a body.
3. Every two years, the national enforcement bodies shall publish reports with statistics on their activity, including on penalties applied by 30 June of the following calendar year. Those reports shall be made available on the website of the European Union Agency for Railways.
4. Railway undertakings shall give their contact details to the national enforcement body or bodies of the Member States in which they operate.