After initial notification of an injury the insurer must decide whether to approve provisional liability for compensation benefits.  This requires the insurer to obtain medical information.  At this stage the information may be in any form, not necessarily on a WorkCover medical certificate.

If the insurer has commenced making weekly payments of compensation the insurer is entitled to request the worker to provide a WorkCover medical certificate covering any periods of incapacity for which payments have been or are to be made.  The WorkCover medical certificate must be used as the information on it provides consent for medical information to be exchanged between relevant parties and also assists the insurer to make decisions about liability and to develop an Injury Management Plan.

Reference:  WorkCover Guidelines for Claiming Compensation Benefits p.9 and p.15.