Units of Issue (U/I) Codes — Complete Reference

Units of Issue (U/I) are two-character codes carried on every National Stock Number (NSN) in the Federal Logistics Information System (FLIS). A U/I code states how an item is packaged, counted, or measured for the purpose of requisitioning and issue — whether it is issued one at a time (EA, Each), by the box (BX), by the can (CN), by the dozen (DZ), by the foot (FT), or by any of several dozen other standard units. The U/I is the element of management data to which the unit price is tied, which is why misreading it is one of the most common — and most expensive — requisitioning errors. Logisticians read the U/I together with the unit price and the Acquisition Advice Code before submitting any requisition.

At a glance

• What it is: A two-position alphabetic code in the FLIS management data describing how an item is packaged, counted, or measured for issue.
• Regulatory source: DoD 4100.39-M (FLIS Procedures Manual), Volume 10, Table 53 — Unit of Issue Codes.
• Maintained in: The Federal Logistics Information System (FLIS), administered by DLA Logistics Information Services; looked up via WebFLIS and FEDLOG.
• Scope: All NSNs in the Federal Catalog; standardized across the military services, DLA, and GSA, and mapped to ANSI ASC X12 values for EDI.
• Where used: Requisition processing (MILSTRIP), cataloging, pricing, stockage, and issue.

What Unit of Issue codes are

The Unit of Issue is one of the core management-data characteristics carried on a National Stock Number. Its purpose is to tell a requisitioner what they are ordering in — the standard quantity, container, or measurement by which the item is issued to the end user.

DoD 4100.39-M defines the Unit of Issue as "a code indicating the physical measurement, the count or when neither is applicable, the container, or shape of an item for purposes of requisitioning by, and issue to, the end-user, and is that element of management data to which the unit price is ascribed."

Three ideas are packed into that definition, and reading them in order is the key to using the code correctly:

1. Physical measurement — for items issued by a measured quantity: foot (FT), yard (YD), gallon (GL), pound (LB), ounce (OZ), meter (MR).
2. Count — for items issued by a number of pieces: each (EA), dozen (DZ), hundred (HD), gross (GR), thousand (MX), pair (PR).
3. Container or shape — when neither a measurement nor a simple count applies: box (BX), can (CN), drum (DR), roll (RO), reel (RL), kit (KT), set (SE).

Critically, the U/I is the basis for the unit price. The price FLIS shows for an NSN is the price for one unit of issue. If the U/I is BX, the price is the price of a box; if it is HD, the price is the price of one hundred. This is why the U/I must be read before any quantity or cost decision is made.

Unit of Issue vs. Unit of Measure vs. Quantity Unit Pack

These three FLIS data elements are routinely confused because they all describe "how much." They are separate fields in separate tables, and they answer different questions.

• Unit of Issue (U/I) — FLIS Table 53. How the item is requisitioned and issued, and the basis for the unit price. This is the field a requisitioner orders against. Example: BX (Box).
• Unit of Measure (U/M) — FLIS Table 81. The standard measurement used to express quantity for stratification, computation, and conversion. The U/M lets the system reason about quantities consistently across NSNs. Example: an item issued by the box (U/I = BX) may be measured in eaches (U/M = EA) so the system knows how many individual pieces a box contains.
• Quantity Unit Pack (QUP) — FLIS Table 56. How many units of issue are in the smallest standard pack for storage and shipment. The QUP tells you how the item is packaged, not how you order it. You can requisition one U/I and still receive it inside a unit pack that contains several.

The short version: U/I is what you order in; U/M is how the system measures it; QUP is how it is packaged. When the three differ, the gap between them is where the costly mistakes happen — most often ordering by U/I while thinking in individual eaches.

How and where the codes are used

The Unit of Issue is one of the first fields a requisitioner checks when looking up an NSN in WebFLIS or FEDLOG. The management data returns the U/I alongside the unit price, the Acquisition Advice Code, the Shelf-Life Code, and the Controlled Inventory Item Code.

• Requisitioning (MILSTRIP). The quantity field on a MILSTRIP requisition is expressed in units of issue. A quantity of 5 against an NSN coded BX requests five boxes, not five individual items.
• Pricing and budgeting. The unit price is the price per unit of issue. Cost estimates built without reading the U/I are wrong whenever the U/I is not EA.
• Cataloging. When an item is cataloged or its packaging changes, the U/I (and any related U/M and QUP) are set or updated in FLIS so downstream systems issue and price it correctly.
• Stockage and inventory. On-hand balances and stockage objectives are carried in units of issue, so a balance of 12 against a DZ-coded item is twelve dozen, not twelve pieces.
• Electronic data interchange (EDI). DoD U/I codes are mapped to ANSI ASC X12 unit-of-measure values so requisitions and catalog data move cleanly between DoD and commercial trading partners.

Because the U/I governs both quantity and price, an out-of-date or misread U/I is a frequent root cause of over-ordering, under-ordering, and budget surprises — see Common errors and gotchas below.

Complete code table

The table below lists the complete set of two-character Unit of Issue codes and their meanings, reproduced from DoD Manual 4100.39 (FLIS Procedures Manual), Volume 10, Table 53 — "Unit of Issue Codes." It is the full authorized code set, including the rarely seen metric, energy, and specialized-commodity units; the everyday codes (EA, BX, CN, DZ, FT, GL) sit alongside them. The "Notes" column gives a plain-English summary; the "Term" matches the code's authorized designation in Table 53. Use the filter to narrow to a code or keyword (for example, "box" or "gallon").

Per Table 53's own note, terms marked with an asterisk (*) in the source manual require a quantitative expression (a count or measurement) to accompany the code — these are the "non-definitive" units of issue (such as box, can, package) where the code alone does not state how many.

Worked example: ordering by the wrong Unit of Issue

A supply clerk needs 100 individual cleaning wipes and pulls the NSN in FEDLOG. The management data shows U/I BX (Box) and a unit price of $24.00.

Reading the price as "per item," the clerk sets the requisition quantity to 100 — intending 100 wipes. But the quantity field is expressed in units of issue, and the U/I is BX. The requisition therefore orders 100 boxes, and the cost is 100 × $24.00 = $2,400.00, not the $24-ish the clerk expected — and far more than 100 wipes.

Reading the U/I first prevents the error. With U/I BX, the clerk checks how many wipes are in a box (the Quantity Unit Pack and any Unit of Measure conversion help here), then requisitions the correct number of boxes — likely a quantity of 1 or 2. The unit price of $24.00 is the price of one box, because price always follows the unit of issue.

The same trap appears with DZ (a quantity of 10 is ten dozen = 120), HD (ten hundreds = 1,000), GR (gross = 144 each), and MX (thousand). Whenever the U/I is not EA, the requisition quantity is not a count of individual items.

Common errors and gotchas

• Treating every U/I as "Each." The single most common mistake. A quantity of 10 against BX, DZ, HD, GR, or MX is ten boxes, ten dozen, ten hundreds, ten gross, or ten thousand — not ten items. Read the U/I before setting the quantity.
• Comparing unit prices without checking U/I. The unit price is the price per unit of issue. An NSN priced "lower" may simply be priced per each while a "higher" one is priced per box. Normalize to a common unit before comparing.
• Confusing U/I with Unit of Measure. U/I is how you requisition and the basis for price (Table 53); U/M is how the system measures quantity (Table 81). They are often the same but can differ — and when they differ, read both.
• Ignoring Quantity Unit Pack. Even when you order the right U/I, the item ships in a standard unit pack (Table 56). Receiving and storage plans should account for the QUP, not just the U/I.
• Assuming the U/I never changes. When packaging changes or an item is re-cataloged, the U/I (and its price) can change. Re-check the current FLIS/FEDLOG record rather than relying on a remembered value.
• Reading the U/I in isolation. The U/I tells you what you are ordering in, but you still need the Acquisition Advice Code to know whether the item can be requisitioned at all, and the Source of Supply / Routing Identifier to know where the requisition goes.

Related codes and cross-references

• Acquisition Advice Codes (AAC) — read alongside the U/I to know how an item is acquired (stocked, local purchase, terminal, condemned) before ordering.
• WebFLIS — the public FLIS query tool that returns the U/I, unit price, and related management data for any NSN.
• FEDLOG / FED LOG — the desktop/offline Federal Logistics Data reference that carries the same U/I and pricing fields.

Authoritative references

• DoD 4100.39-M, Federal Logistics Information System (FLIS) Procedures Manual. The governing manual for FLIS data elements, administered through DLA Logistics Information Services. Published as DoD Manual 4100.39 by the DoD issuances office.
• DoD Manual 4100.39 (DoD 4100.39-M), Volume 10 — Multiple Application References / Instructions / Tables and Grids. Contains Table 53 (Unit of Issue Codes), Table 56 (Quantity Unit Pack Codes), Table 79 (Unit of Issue Conversion Factors), and Table 81 (Unit of Measurement Designations). Archival copy via DTIC.
• Federal Logistics Information System (FLIS). The system of record carrying the U/I as a management-data characteristic on each NSN; queried via WebFLIS and FEDLOG.
• Army Publishing Directorate — Unit of Issue (UI) Codes. A public reproduction of the FLIS U/I code list, used here to cross-check code/meaning pairs: armypubs.army.mil UI codes list.
• DLA Logistics Information Services. Maintainer of FLIS and the Federal Catalog. Defense Logistics Agency — Information Operations.