When contracting with the Department of Defense, there are a few different acronyms that are hugely important to keep track of. IUID, UID, and UII may seem very similar–and are in fact often used interchangeably–but some differences do exist between them.


  • IUID stands for “Item Unique Identification”
  • UID stands for “Unique Identification”
  • UII stands for “Unique Item Identifiers”

Understanding what these acronyms are specifically referring to will help you better understand how they are used and why they are so important.


The Department of Defense Item Unique Identification (IUID) Registry

The U.S. Department of Defense implements standards that require contractors and suppliers to apply a unique identifier to most tangible goods. The framework provided by these standards allows the DoD to efficiently acquire, track, maintain, and deploy the entire population of key assets by giving them visibility into an item’s lifecycle history.

The major goal of the Department of Defense Item Unique Identification (IUID) Registry is to not only improve the quality of supply chain logistical data, but also the speed at which that data can be accessed. The Registry provides a clear chain regarding a particular item’s chain of custody throughout the world, but offers the ability to uniquely identify that item and separate it from every other item (either similar or dissimilar) in existence at any given time.

According to the Department of Defense, items that are submitted to the IUID Registry are those that meet the following criteria:

  • All delivered items submitted which cost $5,000 or more must be added
  • All items costing $5,000 or less that have been identified as mission essential
  • All items costing $5,000 or less that have been identified as a part of a controlled inventory
  • Any Department of Defense serially managed component or part
  • The parent item that contains that particular serially managed component or part.


Unique Identification (UID)

UID has been the term given to the marking that individual items receive upon entry into the DoD IUID Registry. This marking is completely unambiguous within the Department of Defense and distinguishes the item in question and its relationship from other items and relationships within the registry at any given time. Each UID created can be used only once during the lifecycle of that item across the supply chain. The term “UID” is gradually being replaced by “IUID”, as it more accurately represents the compliance standards for the government’s requirements to track physical items such as personal property as opposed to people or real property.


Unique Item Identifier (UII)

The UII is the term given to the “license plate” or data representation of the IUID in a database. The most important thing to understand about the DoD UII system is that this identifier must be globally unique and unambiguous, meaning that no other item of its type in the entire world can have the same identification information for the purposes of tracking.

When tracking something using a UII, a machine-readable designation of characters or numbers (most usually a combination of both) is given to an individual item in order to separate it from any other type of item during transit. This helps provide both the Department of Defense and all contractors with a mechanism for tracking that item at all points from the time the initial transit begins to delivery.


Total Asset Visibility

The reason why IUID, UID, and UII are so important has to do with another acronym commonly used by the Department of Defense: TAV. Short for “total asset visibility,” TAV refers to one’s ability to view instant and accurate information regarding a particular item and any association with a container while in transit.

Total asset visibility guarantees that, at any given moment, a person should be able to view the precise location of an important item, how it has moved, the current status of that item, and exactly what that item is.

Total asset visibility and its required protocols were designed to not only streamline and increase the efficiency of supply chain management within the Department of Defense and all related systems, but also to help prevent things like theft, counterfeiting and more.

These unique identifiers–IUID, UID, and UII–are used to not only record the current whereabouts of an item at all times, but also to shed valuable insight into the condition of a particular asset as it exists within the Department of Defense’s logistics system.