The difference between an item master and an inventory item

What is an item master?

An item master is a master record for a type of inventory item. The item master includes the item description, materials and handling specifications, sales and fulfillment specifications, and warehouse-specific information.

What is an inventory item?

An inventory item is a particular, physical quantity of an item master. The goods in a single inventory item share all of their specific details, such as location and owner, but may have different license numbers. The goods may be soft allocated to different warehouse operations, however, the quantity allocated cannot be more than the total quantity of the inventory item (that is, multiple allocations against a single inventory item do not overlap).

Below is an example of a list of inventory items that are all based on the same item master.

inventory items

Notice that each item is a quantity of the item stored in a particular location and in a particular unit of measure. If you see two inventory line items that otherwise appear the same, each listing has different details that you cannot see from the list view. For example, when you see the first two inventory items in the list above, they appear to be the same. It appears as though the quantities should be merged.

However, if you look at the item details for each inventory item, you'll see that there are details that are different, but those details were not displayed in the initial list view. In this view of the first inventory item, the inventory item has no Owner:

Inventory item same location w/o owner

In the view for the second inventory item, the inventory item has a different Owner.

Inventory item same location with owner

If both of these inventory items had the same Owner, the quantities would have been combined and there would have only been one inventory item with a quantity of 32. However if one of the items had some other distinguishing detail, for example, a serial number or lot number, or if one was put away in cases instead of eaches, they would remain separate line items.

How is an item master different from an inventory item?

An item master is a master record for a type of inventory item. All item masters are set up by a warehouse administrator. The item master includes the item description, materials and handling specifications, and sales and fulfillment specifications.

Inventory items are based on items masters. You can have an item master without any inventory items in stock, but you cannot have an inventory item without an item master.