An apparatus for the collection and storage of user identifiers, wherein the apparatus comprises at least a processor and a memory communicatively connected to the at least a processor. The memory contains instructions configuring the at least a processor to receive user identifier data, identify a plurality of user identifier labels as a function of the user identifier data, extract a plurality of content elements from the user identifier data, classify each content element to an associated user identifier label using a content element classifier, and enter the plurality of user identifier content elements and associated user identifier labels on an immutable sequential listing.