How does SAP Business One decide which account to use when creating a Delivery Document?

When a Delivery is created, SAP credits the Inventory account, and for the debit side, it can either go to:

? COGS account, or
? Shipped Goods account

It all depends on a Customer-Specific Setting: Go to:
Business Partner Master Data > Accounting Tab
Field: ✔️ Use Shipped Goods Account

? If the option is checked, SAP will debit the Shipped Goods account *.

? This feature is especially useful when:
A Delivery is created in one month, and the A/R Invoice is posted in another.
➡️ It helps match Revenue and COGS in the same period.

When the AR Invoice is created SAP will Credit Shipped Goods Account and will Debit COGS account. This is additional to the Customer and Revenue accounts.

? If the option is unchecked, SAP will debit the Cost of Goods Sold (COGS) account * .

 *This account is pulled from the item settings (Item, Item Group, or Warehouse level).

To define the default for new customers, update the global setting:
Navigate to:
Administration > System Initialization > General Settings > BP Tab
Look for the option:
✔️ Use Shipped Goods Account for Customer
 ? This doesn’t affect existing Business Partners — it only sets the default value when a new one is created.