(18)When authorising and supervising third-country branches, competent authorities should be able to exercise their supervisory functions effectively. To that end they need to have access to all the necessary information on the third-country branch’s head undertaking from the supervisory authorities of the relevant third country and be able to effectively coordinate their supervisory activities with those of the third country’s supervisory authorities. Before a third-country branch commences its activities in a Member State, competent authorities should endeavour to conclude an agreement with the supervisory authority of the third country concerned to enable cooperation and information exchange. Such an agreement should be based on the model administrative arrangements developed by EBA in accordance with Article 33(5) of Regulation (EU) No 1093/2010. Competent authorities should submit information about such agreements to EBA. Where the conclusion of an administrative agreement on the basis of the model developed by EBA is not possible, competent authorities should be able to use other arrangements, for example an exchange of letters, to ensure that they can exercise their supervisory functions.