Abstract: This present invention concerns a customization method that represents a saving in time and an increase in yield, in the electronic customization of smart objects in particular, by virtue of:—a stage for establishing communication links between a multiplicity of smart objects held on a portable support, and communication interfaces,—a stage for simultaneous unlocking of the smart objects by means of a first key,—a stage for the parallel transfer into the memory of the smart objects of customization data proper to each of the smart objects, with these data being transferred into at least one memory zone of each smart object,—a stage for the locking of each smart object by means of second keys, each proper to one of the smart objects and each associated with the customization data proper to this object.