---
title: "External item description by unit"
slug: "external-item-description-by-unit"
description: "Link external item descriptions and vendor part numbers to internal item IDs to streamline procurement and supply chain management."
updated: 2026-06-25T10:21:04Z
published: 2026-06-25T10:21:04Z
canonical: "docs.staedean.com/external-item-description-by-unit"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.staedean.com/llms.txt
> Use this file to discover all available pages before exploring further.

# External item description by unit

When purchasing materials from external vendors, the procurement department usually refers to the item number and item description used by the vendors (that is, vendor part number). In Microsoft Dynamics 365 Finance & Supply Chain Management, this information can be associated with a released product using the External item description (**Product information management** > **Products** > **Released products** > **Purchase tab** > **External item description**). The external item description is displayed in purchase orders and in the purchase order confirmation document. It allows to keep the link between the internal and external item identification number and description.

Life Sciences Supply Chain Management allows users to manage different item descriptions for the same item when it is purchased using different units of measure (**Product information management** > **Products** > **Released products** > **Purchase tab** > **External item description by unit**). It is, therefore, possible to define the following values for each combination of item-vendor-unit of measure:

- **External item number**
- **Description**
- **External item text**

It is also possible to make the same external item description valid for multiple vendors by selecting **Group** in the **Account code** field.

> [!NOTE]
> Note
> 
> The **Unit** field in the **External item description by unit** form is mandatory. If the external item description is valid for all units of measure, the Microsoft standard **External item description** form must be used.

For example, if a vendor identifies the Sodium chloride with two different part numbers, one for the 5 kg bag and one for the 10 kg bag, it is possible to record both part numbers in the external item description.

When purchasing the material from the defined vendor and with a specific purchase unit, the **External item number** is displayed in the **Procurement and sourcing** > **Purchase orders** > **All purchase orders** > **Purchase order** > **Line details** > **General** > **External** field and the **External item text** is displayed in the **Purchase order** > **Line details** > **General** > **Text** field.

The **External item number check method** can be used to make the system verify the presence of the vendor part numbers. The check runs when saving the purchase order lines, when releasing a purchase requisition into a purchase order, and when firming a planned purchase order.

The **External item number check method** can be defined in the [**Item check group**](/life-sciences/docs/item-check-group) form (**Inventory management** > **Setup** > **Inventory** > **Item check groups** or **Life Sciences Quality Control & Assurance** > **Setup** > **Inventory** > **Item check groups**) and in the **Released products** form (**Product information management** > **Products** > **Released products**).

The check method verifies if the **External** field (**Procurement and sourcing** > **Purchase orders** > **All purchase orders** > **Purchase order** > **Line details** > **General**) is populated or not and, depending on the **External item number check method** value defined for the item, the system:

- Allows users to save a purchase order line, release a purchase requisition, or firm a planned purchase order if the **External item number check method** is **No check**.
- Displays a warning message allowing users to save a purchase order line, release a purchase order requisition, or firm a planned purchase order, if the **External** field is blank and the **External item number check method** for the item is **Warning only**.

Returns an error message and prevents users from saving a purchase order line, releasing a purchase requisition, or firming a planned purchase order, if the **External** field is blank and the item’s **External item number check method** is **Not allowed**.

## Related

- [Item check group](/item-check-group.md)