Spanish term (edited): asegurado/s nominado/s

The question does not mention which class of insurance or 'assurance' is being taken out, written or 'effected' - speculatively, group life or pension, rather than vehicle-fleet or car-pool policies. So here's a token answer in the absence of such crucial information.

BTW, nomination of a life etc. assurance beneficiary on a *nomination form* takes effect in English probate & succession 'dehors' = outside of any Last Will & Testament made by a testator or testatrix.

The asker, though, should feel free to pick another answer.

I sold insurance for over 15 years. That is the translation