UIN

UIN may refer to:

Common

• User Identification Number, used by many computer security systems and ICQ, see ICQ#UIN, Unique identifier and User (computing)
• Universal Identification Number
  • used for people, see National identification number and Unique Identification Authority of India, see also Permanent account number (PAN)
  • used for inventory, see also UID
• University Identification Number, used by many universities for students, faculty and alumni
• Unit Identification Number, used by the military, see Military unit
• Unit Identification Number, used by the Department of Education, see Integrated Postsecondary Education Data System
• Unique Identification Number, similar to Universal Identification Number used for people and inventory, see above, and often replaced by Universally unique identifier (UUID)

Other uses

• User Intelligent Network, a type of network artificial intelligence, see, for example Personal communications network
• Airport code for Quincy Regional Airport in Illinois, United States