This depends on whether the identity of the beneficiary is known or unknown. Naturally, a good place to start is with the family and friends of the deceased. There are various online search tools available to try and locate people based on clues around their last known location, connections, or employment etc. Beneficiaries may have changed their name and professional help may be needed from an heir finder. The executor has a responsibility to do everything reasonable to try and find a beneficiary and put aside their inheritance until they do.