1.   The requesting authority and the requested authority shall communicate using the most expedient means, taking due account of the following:

(a)	confidentiality considerations;

(b)	correspondence times;

(c)	the volume of material to be communicated;

(d)	the ease of access to the information by the requesting authority.

The requesting authority shall reply promptly to any request for clarifications from the requested authority.

2.   Where a reply cannot be provided by the estimated date or timeframe referred to in Article 4(1), the requested authority shall give a new estimated date or timeframe to the requesting authority explaining the reasons for the delay, using the same means used to acknowledge receipt of the request.

3.   The requested authority and the requesting authority shall cooperate in order to resolve any difficulties that may arise in executing a request.