1.   The requesting authority and the requested authority shall communicate in relation to a consultation notice and the response using the most expedient means from among those set out in Article 4(2) and Article 6(1), taking due account of confidentiality considerations, correspondence times, the volume of material to be communicated and the ease of access to the information by the requesting authority. The requesting authority shall respond promptly to any clarifications requested by the requested authority.

2.   Where the information requested is or may be held by an authority of the same Member State other than the requested authority, the requested authority shall collect the information promptly and transmit it to the requesting authority in accordance with Article 6.

3.   The requested authority and the requesting authority shall cooperate to resolve any difficulties that may arise in executing a request, including resolving any cost issues if the costs of providing assistance are estimated to be excessive for the requested authority.

4.   Where new information or a need for further information arises during the assessment period, the requesting authority and the requested authority shall cooperate to ensure that all additional relevant information is exchanged in accordance with this Regulation.

5.   By way of derogation from Article 4(2) and Article 6(1), where information is being exchanged within the last 15 working days before the end of the assessment period referred to in the second subparagraph of Article 10a(1) of Directive 2004/39/EC, it may be provided verbally. In those cases, that information shall subsequently be confirmed in accordance with Article 4(2) and Article 6(1) unless the competent authorities involved agree otherwise.

6.   The requested authority and the requesting authority shall provide feedback to each other on the outcome of the assessment in relation to which the consultation occurred and, where appropriate, on the usefulness of information or other assistance received or any problems encountered in providing such assistance or information.