---
title: "Automatically Assigning Purchase Order Numbers by the System"
slug: "automatically-assigning-purchase-order-numbers-by-the-system"
updated: 2026-02-25T21:06:09Z
published: 2026-02-25T21:06:09Z
canonical: "help.su-inc.com/automatically-assigning-purchase-order-numbers-by-the-system"
---

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

# Automatically Assigning Purchase Order Numbers by the System

The purchase order numbers can be assigned automatically by the system when entering or copying purchase orders using the [Purchase Orders option](/sui/docs/purchase-orders-option). When entering or copying a purchase order, leave the Purchase Order Number field blank to have the system automatically assign the next available purchase order number once the purchase order is saved.

#### **How the purchase order number is assigned:**

If having the system assign the purchase order number, the system will assign the number as follows:

- First, if the purchase order is tied to a ship to address with a defined purchase order prefix, the number will be incremented from the most recently used purchase order number with that prefix.
- Second, if a purchase order prefix was defined in the Accounts Payable System File, the number will be incremented from the most recently used purchase order number with that prefix.
- Otherwise, the number will be incremented from the most recently used purchase order number.

> **Note:** If the Purchase Order Number Same as Requisition Number field is selected in the Accounts Payable System File, a purchase order number cannot be used if it matches a requisition number that already exists.