Units of Measure (UOMs) are products that represent a specific quantity of a base product. A Pallet, a Master Case, and an Inner Pack are all examples of UOMs. In ShipHero, UOMs are treated like any other SKU — you can receive them, transfer them between locations, and pick and pack them to fulfill orders.
In ShipHero, UOMs are handled the same way as any other SKU during receiving, picking, packing, and shipping.
Important
You cannot store multiple UOMs of the same SKU in the same location. For example, you cannot have a "Cookie Pack" and a "Cookie Case" in the same location.
UOM Types
A UOM can have up to four levels of nesting, from the smallest unit to the largest:
- Pallet → Master Case → Inner Pack → Each
Each level is described in the table below.
| UOM Type | Description | Contains |
|---|---|---|
| Each (Base Product) | The individual unit of a product. A single SKU. This is the building block for all other UOM types. | N/A |
| Inner Pack | A box containing a set number of Eaches, all of the same SKU. If a box contains more than one SKU type, it must be defined as a Kit, not a UOM. | Eaches (one SKU) |
| Master Case | A larger case containing a set number of Inner Packs or Eaches for the same SKU. | Inner Packs or Eaches |
| Pallet | Stacked Master Cases or Eaches placed on a wooden frame. Pallets may not contain mixed SKUs or mixed UOM types. | Master Cases or Eaches |
How UOM Inventory is Calculated
UOMs have their own inventory counts, but the key difference from a regular product is that a component's on-hand quantity includes all of the Eaches contained within any UOMs stored in your warehouse. This article explains how that calculation works and how ShipHero allocates UOM inventory to fulfill orders.
How Inventory Counts Work
When a SKU is the component of a UOM, its on-hand inventory count reflects both its own loose Eaches and the Eaches contained inside any stored UOMs.
Example: Soda Can and Soda 12-Pack
- Soda Can is a base product (Each).
- Soda 12-Pack is a UOM containing 12 Soda Cans.
- Soda Cans are stored in pickable bin A-01.
- Soda 12-Packs are stored in overstock bins C-01 and C-02.
Because Soda Can is a component of the Soda 12-Pack, the Soda Can's on-hand count includes all the individual cans contained within the 12-Packs in C-01 and C-02 — not just the loose cans in A-01.
The same logic applies at every level of a nested UOM hierarchy. When you receive a Pallet, the on-hand counts for all nested components — Master Cases, Inner Packs, and Eaches — update accordingly.
Important: Pickability
If an order is for a specific number of Eaches but your warehouse only has Pallets in stock, the order will not be pickable until the Pallet is broken down into the UOM or Each that matches the order line. Inventory on-hand does not automatically make an order pickable if it is stored in the wrong UOM.
UOM Inventory Allocation Strategy
When ShipHero allocates inventory to fulfill an order, it follows a prioritized strategy to ensure accuracy and minimize unnecessary breakdowns of larger units.
The system first attempts to allocate inventory in the customer's requested UOM (such as Eaches). If that is not possible, it applies the following logic in order:
- Single-unit fulfillment: The system looks for a single UOM unit that completely covers the requested quantity without any remainder.
- Optimal UOM selection: If multiple UOM sizes could fulfill the quantity, the system selects the one that results in the fewest leftover units.
- Largest available UOM: If no single UOM can fully cover the requested quantity, the system selects the largest available UOM to minimize the number of picks required.
This strategy is applied dynamically at the time of allocation. It is designed to reduce availability mismatches, avoid unnecessary UOM breakdowns, and minimize the risk of unexpected backorders.
Related Articles
- How to Create a UOM — create UOMs individually, at the product level, via CSV upload, or directly on the receiving page.
- How to Break a UOM into Smaller Units — break down a Pallet or Master Case into smaller UOMs using the web or mobile app.
- Replenishing Inventory with UOMs — use the mobile app to replenish pickable bins by breaking larger UOMs during the replenishment workflow.