Electronic Duck Stamp Act of 1998 - Amends Federal law to allow the Department of the Interior, the Postal Service, or a State or person authorized to sell Federal migratory bird hunting and conservation stamps to issue representations of such stamps electronically by endorsement affixed to licenses issued at points of sale or through other electronic media.

Permits such States or persons to participate in the issuance of an electronic stamp only if the Secretary of the Interior has approved a plan submitted by the entity that provides for: (1) a satisfactory accounting process for the collection and transfer of revenue; (2) distribution and law enforcement verification of the electronic transaction; and (3) the subsequent distribution of the actual stamp.

Requires such States or persons, not later than 14 days after the issuance of an electronic stamp, to transfer to the Department or designated agent the revenue collected from the issuance by means of an electronic fund transfer method approved by, and compatible with, the Department's or the designated agent's accounting system.