MIL-STD-130 Identification Marking: UIDs and IUID Registry

MIL-STD-130 identification marking requirements tell a defense contractor exactly what to put on a delivered item, how to encode it, and how to report it: every qualifying item needs human-readable text identifying its source and part number, a two-dimensional Data Matrix symbol carrying a Unique Item Identifier, and a matching entry submitted to the DoD’s IUID Registry. The current version is MIL-STD-130N, and compliance is written into most DoD contracts through DFARS clause 252.211-7003.¹ Getting any piece of it wrong is enough to hold up acceptance and payment.

Which Items Have to Be Marked

Cost is the first trigger. DoD policy requires Item Unique Identification for every delivered item with a government unit acquisition cost of $5,000 or more.² Items below that threshold still require marking if any of these apply:

The item is or will be tracked by serial number in a DoD system.
The item supports a critical capability or is managed through a controlled inventory system.
The contracting officer has identified the item in the contract schedule as requiring unique identification regardless of cost.
The contractor decides marking is necessary for operational accountability.

DoD Instruction 8320.04 adds categories that must always be serially managed and marked no matter the price: capital asset equipment, critical safety items, depot-level repairable items, relocatable facilities, and special test equipment tied to major defense acquisition programs.³ Program managers can also flag items vulnerable to counterfeiting or supply chain threats. If an item falls into one of those categories, cost stops mattering.

Exemptions

Two carve-outs sit in DFARS 211.274-2. Items acquired to support a contingency operation, humanitarian mission, peacekeeping effort, or disaster response can be exempted by the head of the contracting activity. And the government can decide it’s more cost-effective to mark items itself after delivery, but only for items bought from small businesses or commercial products acquired under FAR Part 12 or Part 8, and only through a formal Determination and Findings signed by the Component Acquisition Executive for major programs or the head of the contracting activity otherwise. A copy goes to the DoD Unique Identification Policy Office.⁴

Human-Readable Information

Every marked item needs text a person can read without a scanner. At minimum, that text has to identify the source, meaning the manufacturer or supplier’s Enterprise Identifier, and the part or identifying number.⁵ For complete units, groups, or sets, the standard also calls for nomenclature and may require lot numbers, the National Stock Number, or the contract number, depending on the contract.

Formatting is prescriptive. All letters are uppercase sans-serif characters such as Arial, Futura, or Gothic. Numerals are Arabic, and the only permitted symbols are hyphens and forward slashes. Recommended minimum character height is 0.2 cm, roughly 6-point type.⁶ Items designated for IUID must include “UID” as a data area title near the Data Matrix symbol. Labels may also carry a warning like “AUTHORIZED REMOVAL ONLY” or “DO NOT REMOVE.”

The Data Matrix Symbol

The machine-readable component is a two-dimensional Data Matrix symbol, a compact grid of cells that encodes data at high density. The symbology was chosen for how much information fits in a small footprint, which matters when you’re marking a component the size of a coin.⁷

The mark has to survive whatever the item survives. If the item operates in salt spray, extreme heat, or heavy vibration, the symbol must remain legible through all of it for the item’s expected service life. A mark that degrades before the item does is a compliance failure, because the item effectively vanishes from the DoD’s tracking system.

Verification uses quality grading based on ISO/IEC 15415, which evaluates contrast, modulation, and decodability. Every symbol has to meet a minimum verification grade before delivery, and contractors confirm that with a certified barcode verifier, not just a scanner. A scanner only tells you it can read the symbol on that bench, on that day. A verifier tells you the symbol meets the quality threshold that ensures any government scanner in any field condition will read it too.

Building the Unique Item Identifier

The UII is the encoded string that makes the item globally unique in the DoD system. There are two main ways to build one, and a third path for companies already using GS1.

Construct 1

Construct 1 pairs a CAGE code with a serial number. The CAGE code is a five-character alphanumeric identifier assigned by the Defense Logistics Agency to a specific business location.⁸ Organizations that don’t already have one receive a CAGE code when they register in the System for Award Management at SAM.gov.⁹ Under Construct 1, the serial number has to be unique across everything that CAGE code has ever produced.

Construct 2

Construct 2 adds the original part number, so the identifier is CAGE code plus part number plus serial number. This suits manufacturers running several product lines who want to reuse serial number sequences across different parts. The serial number only has to be unique within the combination of CAGE code and part number.

GS1 Equivalents

The DoD accepts two GS1 identifiers in place of a Construct-based UII: the Global Individual Asset Identifier and the Global Returnable Asset Identifier.¹⁰ The GIAI combines a GS1 Company Prefix with an Individual Asset Reference and encodes under Application Identifier 8004. If your commercial supply chain already runs on GS1, this avoids running two parallel serialization schemes.

Encoding Syntax

Whichever construct you use, the data elements get formatted using ISO/IEC 15434 syntax with data qualifiers from ISO/IEC 15418.¹⁰ These standards tell the scanner where each field starts and ends. A single misplaced character invalidates the identifier, so most contractors use dedicated encoding software and verify the output before printing.

Placement and Marking Methods

Placement has to let the mark be read during normal operational use whenever possible.⁶ A technician doing routine maintenance shouldn’t have to disassemble anything to scan the identifier. The mark can go directly on the item or on a plate, band, tag, or label securely fastened to it.

The marking method cannot compromise the item’s structural integrity or function. Common direct part marking techniques include laser engraving, dot peening, chemical (acid) etching, and photo anodizing. When direct marking isn’t feasible, contractors use high-durability adhesive labels, metal stamping on identification plates, or thermal transfer labels for plastic and composite surfaces. Material, operating environment, and required permanency drive the choice.

Reporting to the IUID Registry

Once the physical mark is applied and verified, the identifier has to be reported. Contractors submit UIIs through the Procurement Integrated Enterprise Environment at piee.eb.mil, entering the data as part of the receiving report (DD250) or other shipping and acceptance documentation.¹¹ From there the data flows into the IUID Registry, the central repository storing manufacturer, acquisition date, contract information, and identifier data for every marked item in the DoD inventory.

A successful submission produces a confirmation record, and that record is your proof of compliance. A missing registry entry can hold up payment the same way a missing delivery does. Keep your own log of submitted identifiers so you can reconcile against government records at contract closeout.

Fixing Registry Errors

You have 60 days from the date a record is entered to correct it through PIEE.¹² Corrections can modify static or dynamic data, add information missing from the initial submission such as acquisition cost or acceptance date, or delete a record entirely. The process asks for the UII, the field being changed, the new value, and a reason.

Changing the Enterprise Identifier, batch number, or serial number causes the system to generate a new suggested UII, and you have to accept it. Any change to the UII also means the physical mark on the item has to be updated to match.¹² One trap: embedded items inherit their parent’s acquisition contract information at acceptance. To fix contract data on an embedded item, correct the parent first, and the change propagates down.

Re-Marking After Maintenance or Rebuild

The marking obligation continues past initial delivery. When an item goes through depot-level maintenance, overhaul, or repair, supplemental marking has to be added near the original mark. That supplemental information includes the Enterprise Identifier of the repair facility, the date of the work, any warranty extensions, and the contract or repair order number.⁶ It has to sit near the original mark, read in the same orientation, and match the original’s permanency and legibility. A paper sticker next to a laser-etched identifier will not pass.

For a full rebuild, the standard accepts that some marking methods won’t survive the process. The item has to be marked well enough to last until the rebuild point, and the rebuild facility is responsible for re-applying the original UII data set before the item ships. The UII stays with the item throughout. Rebuilding an item does not give it a new identifier.⁶

1
GovInfo. Defense Acquisition Regulations System, DoD 252.211-7003
2
Federal Register. Defense Federal Acquisition Regulation Supplement; Unique Item Identification and Valuation
3
Department of Defense. DoD Serially Managed Items of Tangible Personal Property and Item Unique Identification 2.0 Standards (DoDI 8320.04)
4
Acquisition.GOV. 211.274-2 Policy for Item Unique Identification
5
DoD Procurement Toolbox. MIL-STD-130N w/Change 1: Identification Marking of U.S. Military Property
6
DoD Procurement Toolbox. MIL-STD-130N: Identification Marking of U.S. Military Property
7
ASSIST-QuickSearch. MIL-STD-130 – Identification Marking of U.S. Military Property
8
Acquisition.gov. 52.204-16 Commercial and Government Entity Code Reporting
9
Defense Logistics Agency. CAGE Code – Commercial and Government Entity Code
10
DoD Procurement Toolbox. Department of Defense Guide to Uniquely Identifying Items
11
Procurement Integrated Enterprise Environment. WAWF Functional Information
12
Wide Area Workflow e-Business Suite. IUID Contractor Correct UID