This is a very broad question and additional information would be needed to understand which country you were specifically interested in to determine the actual requirements, if any, for reporting off-label use without an AE. The FDA website provides information on off-label use.
However in the EU there is the expectation that information about off-label use should be collected for the fulfilment of the PV system and that the MAH would have an appropriate mechanism in place to collect and record relevant information. This information would be expected to be considered in signal management activities and included in the RMPs and PSURs as necessary. GVP modules V, VII and VIII (B.5.9) provide more detail. It should also be noted that Inspection findings have been raised relating to a lack of a process for flagging reports of off-label use not associated with adverse reaction for consideration at the time of PSUR production (ref MHRA).